Is Ethereal Valkyrie legal in Standard, Modern, and Commander?

Ethereal Valkyrie is legal in: Legacy, Vintage, Commander.

Ethereal Valkyrie

Q: What type of card is Ethereal Valkyrie?

Ethereal Valkyrie is a Creature — Spirit Angel. Its oracle text reads: "Flying Whenever this creature enters or attacks, draw a card, then exile a card from your hand face down. It becomes foretold. Its foretell cost is its mana cost reduced by {2}. (On a later turn, you may cast it for its foretell cost, even if this creature has left the battlefield.)"

Creature — Spirit Angel

Flying

Whenever this creature enters or attacks, draw a card, then exile a card from your hand face down. It becomes foretold. Its foretell cost is its mana cost reduced by . (On a later turn, you may cast it for its foretell cost, even if this creature has left the battlefield.)