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

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

What type of card is Paladin Class?

Paladin Class is an Enchantment — Class. Its oracle text reads: "(Gain the next level as a sorcery to add its ability.) Spells your opponents cast during your turn cost {1} more to cast. {2}{W}: Level 2 Creatures you control get +1/+1. {4}{W}: Level 3 Whenever you attack, until end of turn, target attacking creature gets +1/+1 for each other attacking creature and gains double strike."