Oracle Text

Enchantment — Class

(Gain the next level as a sorcery to add its ability.) Whenever a creature you control deals combat damage to a player, exile the top card of that player's library face down. You may look at it for as long as it remains exiled. {1}{U}{B}: Level 2 Creatures you control have menace. {2}{U}{B}: Level 3 You may play cards exiled with this Class, and you may spend mana as though it were mana of any color to cast those spells.