One in eight of Korvosa's wizards are necromancy specialists; that's more than 50 wizards with the feat Command Undead and enough hitdice to control a shadow. Several with enough hitdice to Command multiple shadows, and a small handful with the spell command undead prepared. They'll be enough to protect the Vaults.

As for Toff himself?

He's going to burn Bridgefront down.

Round 91 (12:09:06)

Greater teleport.

Quickened wall of fire.

Oh no.

Round 92 (12:09:12)

Wall of fire.

Quickened fireball.

ORNELOS WHAT THE FUCK ARE YOU DOING.

<Toff, dear boy, is it that you've lost your mind?>

Straight to the fucking histrionics. This is the first Volshyenek has heard about shadows. He's on a different plane entirely, and shadows are hard to see.

That's not the sort of risk you take if you want to live forever.

Then shut up.

Wall of fire.

Remember your place, child.

I made you what you are. Raised you to what power you have.

I can always choose another Ornelos.

Anyway, I can see what you're doing now.

So.

Toodles.

Over half of Korvosa's shadows are still on Endrin Isle, but less than a third of Korvosa's surviving humanoids.

Old Korvosa doesn't connect to the Vaults. It's distant from the Longacre Building and maximally distant to Pharasma's Grand Cathedral. Realistically most of these guys were never going to make it. With a roaring conflagration stretching from Bridgefront halfway to Mainshore, they won't waste time trying. And the fire gives anyone who cares to escape damnation an easy way to off themself. Not that anyone will take Toff up on it, or thank him for the option, since he's the only thinking creature on a planet of mindless zombies.

Shadows could go around the fire, of course. Mainshore isn't far, as the shadow flies. Or they could slip through a gap in the inferno before individual fires have had time to merge some rounds or minutes from now. Or they could fly through under the ground. Or just grit their teeth and walk; 1d6 fire damage per round halved will barely singe them. If a shadow thought about it and were motivated, Toff's little fire would be a trivial inconvenience.

But they won't, because they're stupid. Fire is big and hot and scary and they'd rather go in the opposite direction.

Do you know what's not trivially inconvenient?

Chasing the 6,000 fleeing Korvosans to the north. Pressing them into Garrison Hill, or eventually, the sea.

Directly away from the six districts of Korvosans who ever had a ghost of a chance at surviving the night.

You're welcome.

Round 98 (12:09:48)

Toff still has a wand of fireballs and a few walls of fire in a staff. Scrolls of limited wish he can use to control the wind. He'll keep working Old Korvosa.

Cities burn on a timeframe of hours or days. They're only a major problem for the ninety-nine percent of human societies that waste more time than Korvosans do.

At some point in the future someone will spend 10 minutes casting control weather from a scroll and summon a rainstorm. If Korvosa lasts that long.