where people bet on other people who fight to the death with no rules holding then back at all
(sicairo sometimes show up for quick cash grab)

and the place is run by this guy:

(taken by me)

(yes I am aware this is yoshikage kira)

his name is yoshikage kira, he was a serial killer with a hand fetish before he went to hell, now he enjoys seeing people tearing each other apart for his amusement.

also everything he touches will turn into a bomb.

and he can summon a heat seeking exploding pocket sized tank that's nearly indestructible

(this thing)

and he can make a ghost like image imprint in peoples eyes, when that happens the person is turned into a bomb and can be detonated.

you can say he's on par with alastor.