So mushrooms right? The suppressed earth elemental of the former elemental planes now creamed into a makeshift Prime Material world. They die and cycle back to life through the planet's core. Lest they're killed by artifacts from the few dungeons draining the sealed former Gods.

Which was done in a war effort to ransack dungeons then hunt and track massive elementals. That initiative whipped about all Empires and Kingdoms of the continent but also cleared it of entities of (albeit often accidental) tremendous threat and catastrophies.

Well the energy is still there. And without a corporal form to invest it in all four elemental "wheels" have begun to sprung a makeshift sense of self and agency. Imbuing chosen ones with the status of Avatarship (not to be mistaken with Sorcery, the rare yet natural taint of the "Scared Realm" on its humanoid inhabitants.

Welp colonies of mushrooms work on by mages unaware would be a perfect medium to grant Avatarship to a non corpse (said idiot mage melting his mind into the shrooms inhabiting his body, castle and floor) effectively). Failure to prevent the restoration of his mind by his accolyte will lead to the Earth taking advantage of his rebirthing statue and ov youerrun him/it. Leading the castle (at this point overrun by various druid/mage tempered spores) to turn into a mighty construct. Unleashing on the now human dominated continent a creature which strength matches the (exterminated) great titan's.

Bonus Idea: a mushroom litch