Elegía’s Redemption

You awaken the past memories of a creature that has been risen from the undead, cursed into a new form, or otherwise altered. This does not restore their form but instead they regain their original alignment, mental ability scores, and any languages known. The creature, whose CR cannot exceed 1/3 the caster's level, must fail a Charisma save which it has advantage on if in combat with the caster. The target may receive bonuses or penalties to the save according to the DM, based on the material component used. 

Casting at 7th level raises the CR limit to 1/2 the caster's level while 9th level raises the limit to equal the caster's level.