Is Karador, Ghost Chieftain legal in Standard, Modern, and Commander?

Karador, Ghost Chieftain is legal in: Legacy, Vintage, Commander.

Karador, Ghost Chieftain

Q: What type of card is Karador, Ghost Chieftain?

Karador, Ghost Chieftain is a Legendary Creature — Centaur Spirit. Its oracle text reads: "This spell costs {1} less to cast for each creature card in your graveyard. Once during each of your turns, you may cast a creature spell from your graveyard. *"Death tried to uncrown me. But now I return, king of a greater realm."* Power/Toughness: 3/4"