You can transform into a Dungeon Core that has control over a Dungeon. A Dungeon starts as just a room with a core in it, but with resources it can expand. The Dungeon can use resources to make monsters. The Dungeon Core can turn back to a human, but the Dungeon will be left behind. You can only manage the Dungeon while you are in the Core. If the Dungeon Core is destroyed when you're in it, you're dead, otherwise you just need to start from zero.