Game of Thrones/Lord of the Rings villain swap (warning- major spoilers for season seven of GoT).

[The Romulan Republic]

So, having seen the scene in the last episode where the White Walkers finally breach the Wall by undead dragon fire, and finding myself honestly as impressed, if not more so, as I was by scenes in the Lord of the Rings films, I had to do this.

Scenario:

The armies of Mordor assaulting Minas Tirith (film version) are swapped with the army of the White Walkers assaulting the Wall (TV version, obviously, since the books haven't gotten that far yet).

Scenario One: The host of Mordor (described in LotR merchandise as 200,000 strong as I recall, though I'm not sure if that's just the orcs) finds itself North of the Wall. It consists primarily of orcs, along with numerous siege engines (towers, catapults, and the great ram Grond) manned by trolls, as well as a squad of armored trolls, a smattering of wargs and evil men, a herd of oliphaunts outfitted with war towers full of archers, a squadron of corsair ships (dropped just off-shore in the northern seas), and all nine of the Nazgul on their Fell Beasts, commanded by the Witch King of Angmar. Suddenly cut off from Mordor and his supply lines, the Witch-King does a recon flight over the Wall, sees the greener, inhabited lands on the far side, and decides to invade and plunder them to sustain his forces.

Scenario Two: The army of the White Walkers appears in Osgiliath, a short march across the Pellenor Fields from Minas Tirith. It is comprised of at least a hundred thousand wights (basically fast zombies that can only be killed by fire or a particular type of stone) according to Danaerys, including undead giants and an undead but still fire-breathing dragon, lead by the White Walkers. The White Walkers decide to take Minas Tirith and turn its population into more wights, for whatever reason White Walkers think that's a good idea.

To avoid making this a complete slaughter, presume that Gandalf is somehow aware of the White Walkers' and wights' vulnerability to fire, and informs the garrison accordingly.

All characters are in-character, and any aid that the defenders in either scenario could normally expect can still be expected. The Wall can hope for assistance from the North or Danaerys if they can hold long enough for it to arrive, and the defenders of Minas Tirith will be relieved in about a day by 6,000 Riders of Rohan, closely followed by Aragorn with his own army of the dead.

[FaxModem1]

Scenario Two: The army of the White Walkers appears in Osgiliath, a short march across the Pellenor Fields from Minas Tirith. It is comprised of at least a hundred thousand wights (basically fast zombies that can only be killed by fire or a particular type of stone) according to Danaerys, including undead giants and an undead but still fire-breathing dragon, lead by the White Walkers. The White Walkers decide to take Minas Tirith and turn its population into more wights, for whatever reason White Walkers think that's a good idea.

To avoid making this a complete slaughter, presume that Gandalf is somehow aware of the White Walkers' and wights' vulnerability to fire, and informs the garrison accordingly.

All characters are in-character, and any aid that the defenders in either scenario could normally expect can still be expected. The Wall can hope for assistance from the North or Danaerys if they can hold long enough for it to arrive, and the defenders of Minas Tirith will be relieved in about a day by 6,000 Riders of Rohan, closely followed by Aragorn with his own army of the dead.

Well, I've said it before, but I'll say it again.

Me, in previous thread said:

The White Walkers, for whatever reason, take five years wandering around aimlessly, and the people of Helm's Deep have five years to get ready, and are thus able to make defenses that are able to fight White Walkers.

That's the thing about the White Walkers, they spend most of their time being secluded, and not attacking humans until they either deem themselves ready, it's cold enough for them to be comfortable, or they're waiting for enough political uncertainty in the region that men won't be a threat. Since this doesn't really have a chance of happening in Middle Earth, the White Walkers are more likely to just bugger off and leave the people at Helm's Deep alone for a long time.

That's the big problem with the TV version of the White Walkers, they were on the march all the way back in season 2, but they disappeared shortly after that, meaning they either got lost, or quickly changed their minds about marching.

The White Walkers are so indecisive and slow that the Siege is rather nice for over half a decade due to how slow they are.

[The Romulan Republic]

Heh.

Yeah, they do tend to drag their feet. Which is part of why finally seeing them get off their frozen undead arses was so satisfying.

Me, I think they were waiting to get their hands on a dragon, since the moment they got it they went and blew a hole in the Wall and marched on the North.

Presuming they do actually attack, how would they fair?

[Elheru Aran]

Scenario One depends strongly on whether Mordor's forces have magic enough to overpower the Wall, which is fairly clearly magical in nature. It existed even before the Targaryens invaded IIRC, and that's a LONG time for the Walkers to do fuck-all against it; one has to assume they tried a few different things before the Dragon worked.

And, to be frank, there is little that's very 'magical' about Mordor and Lord of the Rings to start with, standard fantasy tropes notwithstanding. In the books the most impressive thing the Witch-King does is add some magical oomph to the battering ram hitting the gates of Gondor, which admittedly is pretty decent; he doesn't even do that in the movie, mostly existing to swoop menacingly over the battlefield on a fell-beast until the final confrontation with Eowyn. We see that fell-beasts can be hurt by arrows when Faramir hits one in TTT, and in the books Legolas manages to land an arrow on one in FOTR, so they aren't anywhere near as invulnerable as dragons (from either universe). The Night's Watch have *plenty* of bows and arrows.

So, unless they have magic capable of breaching the Wall, and/or can break through the single gate below the Wall, their only real recourse is to take boats around the side, which could take awhile and would be easily met by the Armies of the North and the Night's Watch. Once they made landfall though they could easily use their armoured trolls to establish a beach-head, because that'd be pretty difficult for a medieval army to counter-- they're basically tanks.

Oh, and Scenario Two: Do the White Walkers get their magic ability to turn the weather super-cold? Because that'd be an easy enough win for them-- just turn Gondor into a miniature Antarctica for a few years, build up a few glaciers, stroll casually across the walls of Minas Tirith among the frozen bodies of the guards.

[SpottedKitty]

Scenario One depends strongly on whether Mordor's forces have magic enough to overpower the Wall, which is fairly clearly magical in nature. It existed even before the Targaryens invaded IIRC, and that's a LONG time for the Walkers to do fuck-all against it; one has to assume they tried a few different things before the Dragon worked.

If the swap included Grond, that's going to be a significant help; IIRC it was enchanted with magic to boost its knocking-holes-in-solid-objects ability. Maybe not enough to breach the Wall itself, but if they can find the gates the Night Watch use, it sounds a bit more do-able.

[Solauren]

Why does everyone assume the White Walkers were doing fuck all with their army for 5 years?

The Night's King trashed the Fist of the Fist men in Season 2, and killed alot of the Night's Watch.
It then chased the Freefolk to the wall, and then followed them to Hardhome.

They haven't been sitting on their asses. They've been (admittedly slowly) sweeping all the animal based life out of 'True North' and adding it to the army. The attack on Hardhome was the final lot of reinforcements for them, and they head south.

They were also waiting for winter to appear.


Anyway....

Scenario 2:
The army of the Dead is going to rip apart Helms deep.
Why?
The undead dragon. Breath weapon pass over the battlements, possibly with a dive from above to start (so they don't see him coming) and the defenders are mostly dead. The dragon then turns, breaths again, and the defenders are gone. The Night's King lands, raises his arms, and the dead that are able to, get back up. Army of the Dead swarms into the keep, and slaughters all the civilians.

And when the Riders show up, the dragon deals with them as well.

Realistically, there is nothing on Middle Earth that can stop an undead dragon. Sauron may not get a chance to conquer Middle Earth, cause the Night's King would beat him to it.

=

Scenario 1:
The Ring-Wraiths fly the Fell Beasts over the wall, and proceed to slaughter the Night's Watch and open the gate. If needed, the beasts can fly Orcs up and drop them off, and then the orcs fight their way down.

Once the castle is taken, you move the seige weapons via ships. or disassemble them via the tunnels. Some of the larger creatures could be a pain in the ass to move, but the Orcs have experience building large structures. It shouldn't be that hard to build a walk-way around the base of the Wall. (It's not like 200,000 orcs couldn't cut down the Haunted Forest in a few weeks).

The only chance at this point for the Seven Kingdoms is a nice 'Dragons vs Fell Beast' fight ending with the Ring-Wraiths defeated, and the Orcs to go after and break against Winterfell.

[The Romulan Republic]

Why does everyone assume the White Walkers were doing fuck all with their army for 5 years?

The Night's King trashed the Fist of the Fist men in Season 2, and killed alot of the Night's Watch.
It then chased the Freefolk to the wall, and then followed them to Hardhome.

They haven't been sitting on their asses. They've been (admittedly slowly) sweeping all the animal based life out of 'True North' and adding it to the army. The attack on Hardhome was the final lot of reinforcements for them, and they head south.

They were also waiting for winter to appear.

Well, waiting for Winter is still waiting. But yes, I suppose there's some sense to wanting to consolidate their hold on the North before moving South, and that's a fairly lengthy campaign in and of itself.

Also, as I said, they may have been waiting for a dragon to come North and fall into their hands, so they could use it to breath the wall. They had to have known that any surviving dragons would be choice weapons to send against them, and could have planned to bring one down.

Anyway....

Scenario 2:
The army of the Dead is going to rip apart Helms deep.
Why?
The undead dragon. Breath weapon pass over the battlements, possibly with a dive from above to start (so they don't see him coming) and the defenders are mostly dead. The dragon then turns, breaths again, and the defenders are gone. The Night's King lands, raises his arms, and the dead that are able to, get back up. Army of the Dead swarms into the keep, and slaughters all the civilians.

And when the Riders show up, the dragon deals with them as well.

Realistically, there is nothing on Middle Earth that can stop an undead dragon. Sauron may not get a chance to conquer Middle Earth, cause the Night's King would beat him to it.

Helm's Deep isn't in either of my scenarios (just a former post FaxModem1 quoted). I used Minas Tirith, which is a considerably stronger fortress city. But I agree that Helm's Deep couldn't hold them.

That said, I can think of a few things in Middle Earth that might have a chance against an undead dragon.

-Sauron. He is known to control undead beings himself, and might be able to dominate the dragon and bend it to his will. Not for nothing was he referred to during The Hobbit as "the Necromancer". Though its an unfamiliar type of magic, Sauron's general powers of mental domination are widely-known and employed across multiple races of magical beings, with deadly effect.

-A Middle Earth dragon. Fire breath is a handy weapon against a wight.

-A Balrog. See above reg. fire.

However, none of these would be at Minas Tirith. The only slim chances I can see would be:

a) Massed volleys of flaming arrows.

b) Gandalf. Gandalf the Grey is probably not a match for a Middle Earth dragon like Smaug, or he wouldn't have needed his round-about plan to deal with Smaug. But Gandalf the White is stronger, and has that light beam effect which drove off the Nazgul. Since there is some indication that he has a similar effect on other evil beings and people in the films IIRC, and Gandalf is basically the Middle Earth version of an angel, it is, in my opinion, reasonable to suspect that it has a general "repel evil" effect. It might not kill a wight, but probably it would hurt and/or frighten one.

When Aragorn arrives, he will also have his own army of the dead, since this is film version. Unless the White Walkers could control them (and they're a different kind of undead, following a different kind of magic, bound to follow Aragorn specifically), then I'm not sure what he has that could stop them. But I'm also not sure that their blades would be very effective against wights. A big question mark.

They can't fly like a dragon, though.

=

Scenario 1:
The Ring-Wraiths fly the Fell Beasts over the wall, and proceed to slaughter the Night's Watch and open the gate. If needed, the beasts can fly Orcs up and drop them off, and then the orcs fight their way down.

The Nights' Watch does have archers, though, and the Nazgul, while strong, are not one-man armies, though closer to it in the films than the books, where Aragorn asserts in Fellowship of the Ring that they would be reluctant to attack a well-guarded inn at Bree, unless desperate. Though they are at the height of their power at this point, their main power is fear. The question is weather any of the Nights' Watch would stand its ground in the face of the aura of terror and despair they spread.

They could probably fly high enough to stay above the archers' range, but if they come close to the ground they can be shot, if anyone has the nerve to do it.

Their is the whole thing about the Witch King not being killed by a man, though. Brienne, Arya, or Danny will have to deal with him.

The question is weather

Once the castle is taken, you move the seige weapons via ships. or disassemble them via the tunnels. Some of the larger creatures could be a pain in the ass to move, but the Orcs have experience building large structures. It shouldn't be that hard to build a walk-way around the base of the Wall. (It's not like 200,000 orcs couldn't cut down the Haunted Forest in a few weeks).

Yes, though this will slow them down and allow reinforcements to muster. The corsair fleet in the film doesn't seem terribly impressive, either. A Westrosi navy could probably put it on the bottom without too much trouble, unless the Nazgul were present at the time.

The only chance at this point for the Seven Kingdoms is a nice 'Dragons vs Fell Beast' fight ending with the Ring-Wraiths defeated, and the Orcs to go after and break against Winterfell.

I don't actually like Danny's chances in an aerial battle against all Nine Nazgul. A dragon is far superior to one of the Fell Beasts, sure, but at this point its two on nine, plus the Nazgul's fear aura.

[The Romulan Republic]

Scenario One depends strongly on whether Mordor's forces have magic enough to overpower the Wall, which is fairly clearly magical in nature. It existed even before the Targaryens invaded IIRC, and that's a LONG time for the Walkers to do fuck-all against it; one has to assume they tried a few different things before the Dragon worked.

And, to be frank, there is little that's very 'magical' about Mordor and Lord of the Rings to start with, standard fantasy tropes notwithstanding. In the books the most impressive thing the Witch-King does is add some magical oomph to the battering ram hitting the gates of Gondor, which admittedly is pretty decent; he doesn't even do that in the movie, mostly existing to swoop menacingly over the battlefield on a fell-beast until the final confrontation with Eowyn. We see that fell-beasts can be hurt by arrows when Faramir hits one in TTT, and in the books Legolas manages to land an arrow on one in FOTR, so they aren't anywhere near as invulnerable as dragons (from either universe). The Night's Watch have *plenty* of bows and arrows.

The most powerful Middle Earth magic tends to be subtler. That doesn't mean weaker.

Anyway, the observed powers of the Witch King (film version) include:

-Immortality. Doesn't age, and is at least somewhat supernaturally resistant to physical damage.

-Supernatural fear-aura, like all the Nazgul. Their screeches appear to cause agony, and can leave even hardened soldiers screaming on their knees.

-Striking them with a sword causes pain and injury to the attacker.

-In the extended addition, I believe he telekinetically breaks Gandalf's staff and wields a flaming sword.

-The have supernatural senses, particularly sensing the Ring, though that's not really relevant here.

-Poison/enchanted weapons that will gradually turn you into a wraith if stabbed with them.

I think that's everything. But the only one that matters much for a battle on this scale is the fear aura-type effects. Those can seriously undermine the moral of an army. Well, that and the flight is handy for recon and fast raids.

But yes, arrows are a threat, if the archers stand their ground. But even in their own world, its a rare warrior that will do that.

So, unless they have magic capable of breaching the Wall, and/or can break through the single gate below the Wall, their only real recourse is to take boats around the side, which could take awhile and would be easily met by the Armies of the North and the Night's Watch. Once they made landfall though they could easily use their armoured trolls to establish a beach-head, because that'd be pretty difficult for a medieval army to counter-- they're basically tanks.

Unsullied pike formation, backed up by massed archers and balistas.

Or dragon fire.

Oh, and Scenario Two: Do the White Walkers get their magic ability to turn the weather super-cold? Because that'd be an easy enough win for them-- just turn Gondor into a miniature Antarctica for a few years, build up a few glaciers, stroll casually across the walls of Minas Tirith among the frozen bodies of the guards.

If they could do that on that scale, why do they apparently have to wait for years for winter to come before moving?

Scenario One depends strongly on whether Mordor's forces have magic enough to overpower the Wall, which is fairly clearly magical in nature. It existed even before the Targaryens invaded IIRC, and that's a LONG time for the Walkers to do fuck-all against it; one has to assume they tried a few different things before the Dragon worked.

If the swap included Grond, that's going to be a significant help; IIRC it was enchanted with magic to boost its knocking-holes-in-solid-objects ability. Maybe not enough to breach the Wall itself, but if they can find the gates the Night Watch use, it sounds a bit more do-able.

OP specifies that Grond is along for the ride.

[NecronLord]

Scenario One: The host of Mordor (described in LotR merchandise as 200,000 strong as I recall, though I'm not sure if that's just the orcs) finds itself North of the Wall. It consists primarily of orcs, along with numerous siege engines (towers, catapults, and the great ram Grond) manned by trolls, as well as a squad of armored trolls, a smattering of wargs and evil men, a herd of oliphaunts outfitted with war towers full of archers, a squadron of corsair ships (dropped just off-shore in the northern seas), and all nine of the Nazgul on their Fell Beasts, commanded by the Witch King of Angmar. Suddenly cut off from Mordor and his supply lines, the Witch-King does a recon flight over the Wall, sees the greener, inhabited lands on the far side, and decides to invade and plunder them to sustain his forces.

Poor Elephants.

The Corsairs ferry a few hundred men around behind, they set fire to Eastwatch by the sea and open the gates.

It's pointed out both in show and books that the Night's Watch castles (other than the Nightfort) have no more defences than a fortified house on the southern side.

Zero orc casualties.

[The Romulan Republic]

One wonders, then, why the White Walkers didn't just do the same. They don't have ships, maybe. Could their zombies walk along the seabed, like some other fictional zombies?

I mean, visually, I loved the scene of them tearing down the Wall by dragon fire, but this is bothering me.

[NecronLord]

It's explicitly pointed out last episode that they do not have an ability to swim, and we have never seen them with a ship.

[The Romulan Republic]

It's explicitly pointed out last episode that they do not have an ability to swim, and we have never seen them with a ship.

Alright then.

So yes, Mordor can breach the Wall pretty easily via Corsair fleet (unless the fleet somehow gets sunk/intercepted). Which means the question is more: can the rest of Westeros turn them back once Jon and Danaerys start getting desperate pleas for reinforcements from Winterfell.

[SCRawl]

It's explicitly pointed out last episode that they do not have an ability to swim, and we have never seen them with a ship.

But they can clearly operate underwater. Somebody rigged up the dragons with those chains, after all.

It may be that they can't swim because of buoyancy issues. But there should be nothing stopping them from sinking to the sea floor and walking.

[NecronLord]

Googling, people claim that GRRM has said that the sea is warded against the Others and their Wights beyond Eastwatch.

The Corsairs are men. No warding there. Heavily armed men who outnumber Eastwatch ten to one.

It's doomed.

This tactic has been used successfully on the show:


They have at least three large ships in the film (which is massively lowballing it compared to the books) with mounted weapons and whatever else they were bringing to help besiege a stone-walled city.



Eastwatch is massively fucked.

[The Romulan Republic]

Eh, the film Corsair fleet didn't seem that big. Its kind of weird really- they inflate bad guy army numbers and strength for drama almost everywhere else in the film adaptations, but the Corsair fleet, to my best recollection, is just a few not-so-impressive ships. Certainly not on the scale of the book fleet.

In the books, though, its 50 big ships and an unspecified, but implied to be much larger, number of smaller ones. Probably thousands of troops. And plot-wise is a big enough threat to implicitly draw away the bulk of Gondor's armies from defending their own capital in a desperate war for their very survival. So yeah.

In the films, it comes off as some minor raiders who serve mainly as a plot-device to get Aragorn and company to Minas Tirith on time.

Edits: Which makes me realize that there's a problem with one of my scenarios. If the forces of Mordor, including the Corsairs, are replaced with the White Walkers, Aragorn's reinforcements will be badly delayed, unless he can find some other boats.

[NecronLord]

Eh, the film Corsair fleet didn't seem that big. Its kind of weird really- they inflate bad guy army numbers and strength for drama almost everywhere else in the film adaptations, but the Corsair fleet, to my best recollection, is just a few not-so-impressive ships. Certainly not on the scale of the book fleet.

In the books, though, its 50 big ships and an unspecified, but implied to be much larger, number of smaller ones. Probably thousands of troops. And plot-wise is a big enough threat to implicitly draw away the bulk of Gondor's armies from defending their own capital in a desperate war for their very survival. So yeah.

In the films, it comes off as some minor raiders who serve mainly as a plot-device to get Aragorn and company to Minas Tirith on time.

Edits: Which makes me realize that there's a problem with one of my scenarios. If the forces of Mordor, including the Corsairs, are replaced with the White Walkers, Aragorn's reinforcements will be badly delayed, unless he can find some other boats.

Though as you're taking the films as canonical, literally nothing the White Walkers have can hurt the Army of the Dead. The wights will eventually just get hacked to bits and heaped in a big heap.

[The Romulan Republic]

Maybe so (the only other outcome would be the White Walkers being able to control these dead as well, but that's speculative and seems unlikely to me, for reasons alluded to above). But not necessarily before the White Walkers storm Minas Tirith and kill and resurrect everyone inside.

So, an extremely costly "victory" that leaves Aragorn ruling over a dead and ruined city?

Well, that's suitably bleak and depressing for GoT.

Edit: And actually, while it goes against my OP... if we're strictly faithful to the lore, would the Army of the Dead even fight? IIRC, their oath was specifically to aid Isildur's heir against Sauron (though I can't quite recall if that was specified in the films), not against some other enemy.

[NecronLord]

One dead city but Sauron gone.

Honestly, not that bad.

Gondor is more than Minas Tirith.

[The Romulan Republic]

Well, its not the first dead city Gondor's suffered (cough-Minas Ithil, Osgiliath-cough).

[NecronLord]

So I was thinking about this and, turns out, I'm thinking of the books, where the Nights Watch navy under Cotter Pyke was destroyed at Eastwatch.

In the show, they seem to still be around?

Oops.

[Vendetta]

Scenario One depends strongly on whether Mordor's forces have magic enough to overpower the Wall, which is fairly clearly magical in nature. It existed even before the Targaryens invaded IIRC, and that's a LONG time for the Walkers to do fuck-all against it; one has to assume they tried a few different things before the Dragon worked.

The wall has magic worked into it that prevents creatures of magic from crossing it, somehow. Might stop the ringwraiths from crossing it, but they're nigh unkillable and presumably don't mind the cold.

It would work on orcs about as well as it worked on wildlings. So yeah, the orc army would be able to assault the wall the same as the wildlings did, but they're a larger force and specifically organised and equipped to assault a fortified position, rather than being whatever the wildlings and giants could improvise. In a scenario like the Battle of Castle Black, the forces of Mordor, with the shadow of the Nazgul on their side robbing the defenders of the will to fight and also aerial recon spotting a flanking force like Stannis' in advance, they would gain the wall.

[Tribble]

Is Sauron gone in scenario 2, or just the forces attacking Minas Tirith? If he's still around that might cause problems as the sudden disappearance of his main army and commanders would probably cause him to change plans. Would Frodo still be able to get the Ring to Mount Doom if Sauron is suddenly playing defensively? What would happen if Sauron successfully took it?

[The Romulan Republic]

Is Sauron gone in scenario 2, or just the forces attacking Minas Tirith? If he's still around that might cause problems as the sudden disappearance of his main army and commanders would probably cause him to change plans. Would Frodo still be able to get the Ring to Mount Doom if Sauron is suddenly playing defensively? What would happen if Sauron successfully took it?

Just the Minas Tirth army. Although... could all of Sauron's creatures, particularly the Nazgul, even function without some connection to him? Probably not. So Sauron will still have to be telepathically connected to them in some way.

The army at Minas Tirith was hardly his only army, in any case. Perhaps not even his largest.

He might play more cautiously for a while, until he knows what happened. Maybe let the White Walkers and Gondor bleed each other before mopping up the survivors. Though that could backfire spectacularly if the White Walkers win and add the dead to their own numbers (Cersei should have considered this too, perhaps).

Or he might get more aggressive.

If he gets the Ring back, its gain over, for sure. Even without the army at Minas Tirith, he'll be more than strong enough to win, especially if Gondor is bled dry fighting the White Walkers. And especially if he can ultimate coopt the White Walkers.

The biggest loss for him is losing all nine Nazgul and their rings, which makes this a worse loss for him than canon Pellanor Fields. But still not an insurmountable one, I think. Especially with the White Walkers overrunning Gondor.

[NecronLord]

The host at the Pelannor Fields was only a portion of the strength of Mordor, and the forces at the Morannon outnumbered them significantly, in both the book and film versions.

[Tribble]

And as always in a LOTR scenario we have to take into account the Valar (and possibly Eru). While the Valar had laid down their official guardianship of Middle Earth they still sent the Istari over to Middle-Earth to help challenge Sauron. Clearly they felt that they hold some degree of responsibility, even if they did not fight Sauron directly. White walkers suddenly appearing out of nowhere and trashing Minas Tirith while Sauron regains the Ring, possibly gains control of the White Walkers and launches his own slaughter campaign is the kind of the thing which could provoke the Valar into taking some form of direct action. I don't see the White Walkers and Sauron posing much of a challenge to the Valar if it came down to it.

Eru of course could wipe them all out in an instant though I assume that since the White Walkers didn't get destroyed the moment they entered Middle-Earth he allowed the swap to take place.