Is Sailors' Bane legal in Standard, Modern, and Commander?

Sailors' Bane is legal in: Legacy, Vintage, Commander.

Sailors' Bane

Q: What type of card is Sailors' Bane?

Sailors' Bane is a Creature — Dragon Turtle. Its oracle text reads: "This spell costs {1} less to cast for each card you own in exile and in your graveyard that's an instant card, a sorcery card, or a card that has an Adventure. Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)"

Creature — Dragon Turtle

This spell costs less to cast for each card you own in exile and in your graveyard that's an instant card, a sorcery card, or a card that has an Adventure.