Wildermyth: The Vulture

[Part of the Cursed story line]

Deep within the mountain the squad finally finds the Vulture Lord, an evil hungry god had been locked in there until Dranalla and company's battle with the Deepists all those months ago had inadvertently set him free. He is a strong spell caster in his own right but worse, he cannot actually be killed until his sun altar is destroyed as it continually revives him.

This results in a long battle of dancing around his AoE's while also keeping his endless adds at bay. The Vulture manages to get his magic hands on Zefelle at one point and forces her gem-eye condition to worsen exponentially, killing her by calcification into mineral. Her compatriots destroy the altar soon after and finally put down the evil god once and... oh right, he still can't be killed.

Even without the altar their "dying" foe laughs at them, taunting that he will still regenerate - it will just take a little longer (years instead of minutes). Thus the (barely) survivors decide to take a page out of Castlevania and hack him into pieces, each taking a body part to hide and secure in distant parts of the world.