Is Fire Lord Ozai legal in Standard, Modern, and Commander?

Fire Lord Ozai is legal in: Legacy, Vintage, Commander, Historic.

Fire Lord Ozai

Q: What type of card is Fire Lord Ozai?

Fire Lord Ozai is a Legendary Creature — Human Noble. Its oracle text reads: "Whenever Fire Lord Ozai attacks, you may sacrifice another creature. If you do, add an amount of {R} equal to the sacrificed creature's power. Until end of combat, you don't lose this mana as steps end. {6}: Exile the top card of each opponent's library. Until end of turn, you may play one of those cards without paying its mana cost."

Legendary Creature — Human Noble

Whenever Fire Lord Ozai attacks, you may sacrifice another creature. If you do, add an amount of equal to the sacrificed creature's power. Until end of combat, you don't lose this mana as steps end.