Is Everdream legal in Standard, Modern, and Commander?

Everdream is legal in: Modern, Legacy, Vintage, Commander.

Everdream

Q: What type of card is Everdream?

Everdream is an Instant. Its oracle text reads: "Draw a card. Splice onto instant or sorcery {2}{U} (As you cast an instant or sorcery spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)"

Instant

Draw a card.

Splice onto instant or sorcery (As you cast an instant or sorcery spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)