Fourth Age Past Lives

[Thalia]

There’s a page to add hero of the horn details when you’ve decided them: https://thefirstage.org/wiki/heroes-of-the-horn/

Asc did a page for Ged if that’s helpful, and in case there’s anything you want to adjust (it does already say that he passed his crown to Osiris): https://thefirstage.org/wiki/ged/

Atharim origins is 6th Age when people turned on the gods so yep he’d have been gone before then.

I don’t think it’s possible to be untied from the Horn, once bound it’s permanent, and that soul will always be called (unless they happen to be alive when the Horn is blown). Though not all other lives have to be heroic so you could still easily do the cycle of lives across ages around redemption.