Childe has a pretty good chance of becoming the fifth descender, or at least a being that can rival the gods. But he has to lose his vision and die first.
It's complicated, but his background mirrors Ajax' legend.
Ajax was a man who fell into the abyss and was stripped bare of all his human components. There he was reborn as a "holy newborn", or as they called it in the order, a primal human.
According to leaks Durin is also a primal human and the existence of primal humans on Teyvat is what has Skirk going to Nod Krai as well as Phanes awakening before fully healing.