Lúthien?
Being endowed with a high power
She is half-Ainu.
But helpless to the hands of fate
Tied to Beren.
Enriched the lore
Uh . . .
Awakened hate
Awakened the Oath of Fëanor through the Quest of the Silmaril, which was done for her.
Was granted love in final hour.
She died and rescued Beren before he was sent away.