Is Karn's Sylex legal in Standard, Modern, and Commander?

Karn's Sylex is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Karn's Sylex

Q: What type of card is Karn's Sylex?

Karn's Sylex is a Legendary Artifact. Its oracle text reads: "Karn's Sylex enters tapped. Players can't pay life to cast spells or to activate abilities that aren't mana abilities. {X}, {T}, Exile Karn's Sylex: Destroy each nonland permanent with mana value X or less. Activate only as a sorcery."