Diablo

Diablo

Diablo spawns in the center of the Halloween Zone during (Night Time). If you kill enough of his friends (npcs in the zone), he will pick a boss at random and spawn them in the zone.

The higher the level the zone is scaled to, the more bosses Diablo is able to pick from and spawn (e.g. mobs scaled to level 77 will only have a chance to spawn Cazic thru Arcing Demon)