When Cacophony Unleashed enters the battlefield, if you cast it, destroy all nonenchantment creatures. Whenever Cacophony Unleashed or another enchantment enters the battlefield under your control, until end of turn, Cacophony Unleashed becomes a legendary 6/6 Nightmare God creature with menace (This creature can't be blocked except by two or more creatures.) and deathtouch (Any amount of damage this deals to a creature is enough to destroy it.). It's still an enchantment.