Is Zhalfirin Knight legal in Standard, Modern, and Commander?

Zhalfirin Knight is legal in: Legacy, Vintage, Commander, Pauper.

Zhalfirin Knight

Q: What type of card is Zhalfirin Knight?

Zhalfirin Knight is a Creature — Human Knight. Its oracle text reads: "Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.){W}{W}: Zhalfirin Knight gains first strike until end of turn."

Creature — Human Knight

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)<br>: Zhalfirin Knight gains first strike until end of turn.

Set Mirage

Rarity Common

Artist John Bolton