Is Fervent Champion legal in Standard, Modern, and Commander?

Fervent Champion is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Fervent Champion

Q: What type of card is Fervent Champion?

Fervent Champion is a Creature — Human Knight. Its oracle text reads: "First strike, haste Whenever this creature attacks, another target attacking Knight you control gets +1/+0 until end of turn. Equip abilities you activate that target this creature cost {3} less to activate."