Yes, T15 is a real step up. I had one good run where I got to the seekers with 2 min left. Guess what, they had 90% HP left when the timer ran out. The conduit shrine all but tickled them. Getting a key with those vampire mages, who spawn immunity blister thingies on the edge of the screen, is an instant F. They seem to be everywhere or my luck just ran out.
I just leave the abattoir when i spot those vampires 🤣 idk why but if you wait some minutes outside the abattoir, it reset the dungeon! mayyyyyybe resetting until spiders/skull maybe helpful... but i doubt it