Is Visions of Duplicity legal in Standard, Modern, and Commander?

Visions of Duplicity is legal in: Legacy, Vintage, Commander.

Visions of Duplicity

Q: What type of card is Visions of Duplicity?

Visions of Duplicity is a Sorcery. Its oracle text reads: "Exchange control of two target creatures you don't control. Flashback {8}{U}{U}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)"

Sorcery

Exchange control of two target creatures you don't control.

Flashback . This spell costs less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)