Is Fighter Class legal in Standard, Modern, and Commander?

Fighter Class is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Fighter Class

Q: What type of card is Fighter Class?

Fighter Class is an Enchantment — Class. Its oracle text reads: "(Gain the next level as a sorcery to add its ability.) When this Class enters, search your library for an Equipment card, reveal it, put it into your hand, then shuffle. {1}{R}{W}: Level 2 Equip abilities you activate cost {2} less to activate. {3}{R}{W}: Level 3 Whenever a creature you control attacks, up to one target creature blocks it this combat if able."