Is Errant Ephemeron legal in Standard, Modern, and Commander?

Errant Ephemeron is legal in: Modern, Legacy, Vintage, Commander, Pauper.

What type of card is Errant Ephemeron?

Errant Ephemeron is a Creature — Illusion. Its oracle text reads: "Flying Suspend 4—{1}{U} (Rather than cast this card from your hand, you may pay {1}{U} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)"

Errant Ephemeron

Creature — Illusion

Flying

Suspend 4— (Rather than cast this card from your hand, you may pay and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)