False Divinity!
Marvin hadn't dreamt that Endless Ocean would give him such a huge gift!
He already knew that regardless of which doppelganger was killed, there would be some Divine Power left. Auzin was the second son of the World Ending Twin Snakes after all.
But with so many Legends here, Marvin hadn't thought of aiming for the Divine Power.
What's more, even if he wanted that divinity, he didn't have any vessel for it, or else he could have kept the Divine Power from the Lich's finger for himself.
But he now had a False Divinity!
A False Divinity could be anything that could imitate a Divinity's ability to store Divine Power. It might a kind of celestial magic item or it might be a product of alchemy.
Endless Ocean's False Divinity seemed to be from an adventure in a different plane, and it looked like she and Constantine had similar things.
This bit of Divine Power completely transformed Marvin's body!