Awaken Undead

After spending the casting time tracing magical runes on the target with the black sapphire, you touch a medium or smaller undead which must be there for the entire casting of the spell. The target must have either no Intelligence score or an Intelligence of 7 or less. The target gains the Intelligence it had in life or 10 whichever is lower. The target also gains the ability to speak one language you know. The target does not regain any knowledge it had in life.

If the awakened undead was under your control when this spell is cast it regards you as a friend, and its alignment now matches yours. If the awakened is not under the control of any body it must make a Charisma saving throw on a fail it is charmed by you for 30 days or until you or your companions do anything harmful to it. When the charmed condition ends, the awakened undead chooses whether to remain friendly to you, based on how you treated it while it was charmed, regardless its alignment does not change to match yours.

If the awakened undead was under the control of another creature, that controlling creature makes the Charisma saving throw instead.

If the creature is later resurrected (such as through a  True Rsurrection spell) the awakened undead can make a Charisma saving throw against the effect, it makes that saving throw with Disadvantage. On a failed save the awakened undead is destroyed and reformed as the resurrected creature, the resurrected creature does not retain any of the awakened undead's memories.