The Corrupt Heart is the true final boss, only accessible after collecting three keys. It's an incredibly difficult fight, testing every aspect of your deck. It has immense HP, applies numerous debuffs (Vulnerable, Frail, Weak), deals massive damage, and has a unique 'Beat of Death' mechanic that deals 1 damage for every card played. You need a highly optimized deck with strong damage, block, and status effect mitigation to stand a chance. This is the ultimate challenge.
