Is Triton Wavebreaker legal in Standard, Modern, and Commander?

Triton Wavebreaker is legal in: Modern, Legacy, Vintage, Commander, Historic.

Triton Wavebreaker

Q: What type of card is Triton Wavebreaker?

Triton Wavebreaker is an Enchantment Creature — Merfolk Wizard. Its oracle text reads: "Bestow {1}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.) As long as this permanent is a creature, it has prowess. (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) Enchanted creature gets +1/+1 and has prowess."