Heck

Heck is a recurring arena present in every season so far based very loosely on the fact that Ultimate Custom Night is all but confirmed to take place in a tormenting afterlife for William Afton, though it doesn't actually share any traits with the establishment seen in that game.

Layout
The main area of the arena is a large brimstone platform in the depths of a very hot cavern. Boiling lava sits in a river surrounding this platform, and may erupt upwards or even overtake parts of the arena at random times. There are a few narrow caverns that loop around.

Gimmicks

 * Lava can spray upward or melt down pieces of the arena, making it progressively smaller.

Trivia

 * This is one of the few arenas to make an appearance in every season of User Battles.