Stuck in boss arena, boss outside of arena, can't leave.

Bug Report ID: #2072974129

I'm in the Derelict Mansion map. Varloch spawned on the piano while I was walking inside, Avelyne spawned in the middle. I killed Avelyne and Varlock clipped through the wall.

Now he's trapped out there and I'm trapped in here. Portals don't work. I've quit to desktop as well as just to login screen. I still come back in stuck.

What do I do?