Irasil

when the bramblebriar woods was cursed by the great witch tessamine by someone insulting her (thus infamously changing her title from the herald of the wood to the harlot of the wood), a thick miasma lingered about for decades, slowly decaying the wood and killing both the animals and the elves that once called it home. the bravery of one lone elf stepped up to fight the curse, but his wards didn't mix with the witch's ancient magic. realizing that more damage could be done by his attempt, he absorbed his magic and some of the curse into himself, mutating into a strange half-elf, half-creature. however, his attempt wasn't all for naught, as his ward proved powerful enough to prevent the curse from spreading. due to his sacrifice, he became a guardian of the wood, and most elves beyond the northern peninsula (and some humans) venerate him as their god. 

before he entered the bramblebriar woods, however, irasil was actually a cruel and sadistic man obsessed with power. he was said to have felled legions with his impressive magic, doing all he can to conquer where he walked. hearing of the ancient magic used in the woods, irasil wanted to absorb it and utilize it for his own, but his plan backfired when he got tainted by it. using wards did little to save him, and though it saved most of his former body, the mixture of magics still mutated him. this also muddled his mind, and when he came to after his transformation, he had little knowledge of who he was beside his name. his life and bloodthirsty nature up until that moment was wiped from memory, leaving him a blank slate. however, despite his hesitantions, time eventually humbled him and he began to protect the cursed part of the bramblebriar woods. his reassurances to the elves that lived on in the healthy part of the forest led to him being recognized as a god of the wood, leading to his veneration as one. 

the northern and eastern tribes have made it their mission to ensure the curse of the forest doesn't spread, as irasil's ward is powerful but still needs to be maintained. this is done by nominating a young elf every 50-100 years to go on a pilgrimage where, at the end, they will sacrifice their life to the ward to keep it maintained. elyndra was chosen as a volunteer after some problems, but she doesn't take to it well, and escapes to a life of her own after distracting her ward, ivarn, leading to a desperate chase to find her. 

after learning that irasil's continued existence in the cursed part of the wood actually extended the curse rather than keeping it at bay (his ward was described as putting a stopper on a leaking jug of water; without the ward, the curse would've "evaporated" and allowed the wood to heal completely 400 years before), elyndra mercy kills him so that the woods might heal. in doing so, the ward becomes erratic, and elyndra willingly absorbs it so that it might not rupture and damage the wood. in doing so, the essence fueling it for years merges with her own, extending her life instead of ending it as she figured. her braveness in the face of possible sacrifice has her recognized as a hero, and she is quickly thrust into legend as the undying hero of the bramblebriar woods. 

ivarn is his direct descendent from the daughter irasil sired before entering the bramblebriar woods. however, ivarn never comes to learn this despite looking into his background.