Ethereal

Ethereal is earned by completing the Caves with a Cleric cat. This unlocks the Ethereal active ability, a powerful defensive buff that costs 16 mana and grants 4 Holy Shield, 3 Shield, 2 HP healing, and 1 Brace all at once. The upgraded version adds 6 Thorns and 5 Reflect on top of all that, turning your Cleric into a walking damage reflector. Pairs well with Body Guard, which lets you redirect these buffs to protect allies. Expensive to cast, but the sheer volume of defensive layers makes it worth building around.