Is Sun Warriors legal in Standard, Modern, and Commander?

Sun Warriors is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Sun Warriors

Q: What type of card is Sun Warriors?

Sun Warriors is a Creature — Human Warrior Ally. Its oracle text reads: "Firebending X, where X is the number of creatures you control. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.) {5}: Create a 1/1 white Ally creature token."