Is Dawning Purist legal in Standard, Modern, and Commander?

Dawning Purist is legal in: Legacy, Vintage, Commander.

Dawning Purist

Q: What type of card is Dawning Purist?

Dawning Purist is a Creature — Human Cleric. Its oracle text reads: "Whenever this creature deals combat damage to a player, you may destroy target enchantment that player controls. Morph {1}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)"