Is Sokka, Swordmaster legal in Standard, Modern, and Commander?

Sokka, Swordmaster is legal in: Legacy, Vintage, Commander, Historic.

What type of card is Sokka, Swordmaster?

Sokka, Swordmaster is a Legendary Creature — Human Warrior Ally. Its oracle text reads: "Vigilance Equipment spells you cast cost {1} less to cast for each Ally you control. At the beginning of combat on your turn, attach up to one target Equipment you control to Sokka."