Is Tomb Blade legal in Standard, Modern, and Commander?

Tomb Blade is legal in: Legacy, Vintage, Commander.

Tomb Blade

Q: What type of card is Tomb Blade?

Tomb Blade is an Artifact Creature — Necron. Its oracle text reads: "Flying Whenever this creature deals combat damage to a player, that player loses life equal to the number of creatures they control unless they sacrifice a creature of their choice. Unearth {6}{B}{B}"

Artifact Creature — Necron

Flying

Whenever this creature deals combat damage to a player, that player loses life equal to the number of creatures they control unless they sacrifice a creature of their choice.

Unearth