Is Supreme Exemplar legal in Standard, Modern, and Commander?

Supreme Exemplar is legal in: Modern, Legacy, Vintage, Commander.

Supreme Exemplar

Q: What type of card is Supreme Exemplar?

Supreme Exemplar is a Creature — Elemental. Its oracle text reads: "Flying Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)"

Creature — Elemental

Flying

Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Set Morningtide

Rarity Rare

Mana Value 7

Artist Mark Tedin

Collector # 53

Scryfall Gatherer