Is Keldon Flamesage legal in Standard, Modern, and Commander?

Keldon Flamesage is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Keldon Flamesage

Q: What type of card is Keldon Flamesage?

Keldon Flamesage is a Creature — Human Shaman. Its oracle text reads: "Enlist Whenever this creature attacks, look at the top X cards of your library, where X is this creature's power. You may exile an instant or sorcery card with mana value X or less from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost. Power/Toughness: 2/3"

Creature — Human Shaman

Enlist

Whenever this creature attacks, look at the top X cards of your library, where X is this creature's power. You may exile an instant or sorcery card with mana value X or less from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost.

Power/Toughness: 2/3

Set Dominaria United

Rarity Rare

Mana Value 3

Artist Jason A. Engle

Collector # 135

Scryfall