BogMod/AbyssalRedemption
From Exalted - Unofficial Wiki
If an abyssal ever achieves redemption, it is known they lose all necromancy powers and can never again learn necromancy. This is for a reason, part of what allows someone to weild necromancy is a link to the power of the underworld and the malfeans. When a solar becomes an abyssal the Great Curse is changed and altered. Then when the redemption occurs the now changed Great Curse is broken to leave the solar free of the Great Curse forever more.