Is Dauthi Mercenary legal in Standard, Modern, and Commander?

Dauthi Mercenary is legal in: Legacy, Vintage, Commander, Pauper.

What type of card is Dauthi Mercenary?

Dauthi Mercenary is a Creature — Dauthi Knight Mercenary. Its oracle text reads: "Shadow (This creature can block or be blocked by only creatures with shadow.) {1}{B}: This creature gets +1/+0 until end of turn. *"The Dauthi believe they dignify murder by paying for it." —Lyna, Soltari emissary* Power/Toughness: 2/1"