Is Restless Fortress legal in Standard, Modern, and Commander?

Restless Fortress is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Restless Fortress

Q: What type of card is Restless Fortress?

Restless Fortress is a Land. Its oracle text reads: "This land enters tapped. {T}: Add {W} or {B}. {2}{W}{B}: This land becomes a 1/4 white and black Nightmare creature until end of turn. It's still a land. Whenever this land attacks, defending player loses 2 life and you gain 2 life."