Is Triangle of War legal in Standard, Modern, and Commander?

Triangle of War is legal in: Legacy, Vintage, Commander.

Triangle of War

Q: What type of card is Triangle of War?

Triangle of War is an Artifact. Its oracle text reads: "{2}, Sacrifice Triangle of War: Target creature you control fights target creature an opponent controls. (Each deals damage equal to its power to the other.)"

Artifact

, Sacrifice Triangle of War: Target creature you control fights target creature an opponent controls. (Each deals damage equal to its power to the other.)