The nearest to Brigit-freeer hero I can think of is Sigfried/sigurdr, so you would expect a dragon slayer to rescue the valkyrie, errr... angel, from her circle. Which in Erebus probably means a Grigori Dragon-Slayer.
Said dragon-slayer probably started out as a hero, but a mere warrior, he spent his young years learning smithing (staid idle gaining xp in capital) and forged himself a sword out of the broken weapon of his father (upgraded to iron weapons). Sigurdr then moved on and became dragon-slayer: He was the one who gave Acheron the death blow, and he almost drowned in the beast's blood. He managed to swin of the blood, severely burnt, and spent days to recover. After this period of rest, he realised that the blood had hardened his skin, and that he now understoof the language of the Birds.
As he left the city, his winged friends told him about a winged maiden, imprisoned in a forsaken place. She was held there since times immemorial and had only been able to ask a dove for help before dark forces bound her. The dove told the story to other birds, and birds kept telling it generation after generation, hoping some day a bird would find the hero that the winged woman awaited.
Sigurdr set on a quest to find the angel. He followed the bird through orcish jungles, fighting the Clan on his way till he reached the wintery lands of the Doviello. Sigurdr fought these barbarous men and almost died to the fierce blizzards until finally he reached the Ring the dove had talked him about.
Even he was afraid of the terrible ring of shimmering lights beyond which he couldn't see, but he had fought orcs and goblins, savages of all kinds, and killed a Dragon. He was the best warrior among the Grigori, the people who are not afriad of gods. Why should he fear this? He strode forward, sword in hand, and would lift the spell and free the angel.