Is Emberheart Challenger legal in Standard, Modern, and Commander?

Emberheart Challenger is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Emberheart Challenger

Q: What type of card is Emberheart Challenger?

Emberheart Challenger is a Creature — Mouse Warrior. Its oracle text reads: "Haste Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, exile the top card of your library. Until end of turn, you may play that card."

Creature — Mouse Warrior

Haste

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, exile the top card of your library. Until end of turn, you may play that card.

Set Bloomburrow

Rarity Rare

Mana Value 2

Artist Chris Rahn

Collector # 133

Scryfall Gatherer