Is Zirda, the Dawnwaker legal in Standard, Modern, and Commander?

Zirda, the Dawnwaker is legal in: Modern, Pioneer, Vintage, Commander, Historic. It is banned in: Legacy.

Zirda, the Dawnwaker

Q: What type of card is Zirda, the Dawnwaker?

Zirda, the Dawnwaker is a Legendary Creature — Elemental Fox. Its oracle text reads: "Companion — Each permanent card in your starting deck has an activated ability. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.) Abilities you activate that aren't mana abilities cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana. {1}, {T}: Target creature can't block this turn."

Legendary Creature — Elemental Fox

Companion — Each permanent card in your starting deck has an activated ability. (If this card is your chosen companion, you may put it into your hand from outside the game for as a sorcery.)