Hero Realms: Lich Boss Deck - Rules of Play says:
Use your dark magic to corrupt the minds of the living and summon forth a legion of the dead! This Boss Deck replaces your personal deck in the Hero Realms Deckbuilding Game. With it, play against 1-5 players using Hero Realms Character Packs or against another Boss Deck. Included are 30 cards: A Lich character card, a Corruption card, 10 starting-deck cards, 10 Grimoire Minion cards, 6 Soul Jar cards, and two unique score cards.