Brim

A tiny guy (4') with ashened hair hanging over his eye, a blue glowing bulb of ooze with tiny butterfly wings which appears to come out from the left side of his skull it seems to also come from his eye, a gray turn cloak stolen from one of his siblings bodies littering the battlefields, with a broken blunt sword attached to his back. He looks sad.

They are a child of a god king. Billions born every so often only to fight and win the war against another god their father has be fighting for centuries. All they know is battle and survival as the beasts the enemy god has created kills their siblings by the dozen and are giant like creatures mashed with an animal or two. One day they will win, Brim is not one of the lucky few who survived an attack from a spider lion. He did die in that but his godling body allowed for something to crawl into his dying corpse. The crack in his skull allowed for a parasite like ooze to bring him back right before his last breath. Once woken up again Brim felt a small bulb of the parasite trying to yank it out which resulted in a dizzy spill. Leaving it be and hiding away in a small hole dug at some point in the war. He reflected about himself, the war, his father, and most importantly his siblings. Under the glow of the bulb he realized that it was helping him have less of a one track mind, after accepting this as part of him the bulb grew butterfly wings as a symbol of their symbiosis. Brim began to fight for a different reason, for his siblings to end their suffering and the deaths of so many.

The ooze in his head gets incorporated to some of his energy work. Still a tiny titan beast killer but focused on saving his siblings.

think hollow knight if the vessels could speak and have their own thoughts.