Is The Skullspore Nexus legal in Standard, Modern, and Commander?

The Skullspore Nexus is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

The Skullspore Nexus

Q: What type of card is The Skullspore Nexus?

The Skullspore Nexus is a Legendary Artifact. Its oracle text reads: "This spell costs {X} less to cast, where X is the greatest power among creatures you control. Whenever one or more nontoken creatures you control die, create a green Fungus Dinosaur creature token with base power and toughness each equal to the total power of those creatures. {2}, {T}: Double target creature's power until end of turn."

Legendary Artifact

This spell costs less to cast, where X is the greatest power among creatures you control.

Whenever one or more nontoken creatures you control die, create a green Fungus Dinosaur creature token with base power and toughness each equal to the total power of those creatures.

, : Double target creature's power until end of turn.