Is Combat Celebrant legal in Standard, Modern, and Commander?

Combat Celebrant is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Combat Celebrant

Q: What type of card is Combat Celebrant?

Combat Celebrant is a Creature — Human Warrior. Its oracle text reads: "If this creature hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)"

Creature — Human Warrior

If this creature hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)

Set Amonkhet

Rarity Mythic Rare

Mana Value 3

Artist Chris Rallis

Collector # 125

Scryfall Gatherer