D&Dtools1

This spell tears the foul, corrupted soul from the body of an evil creature and traps it in a diamond receptacle (the spell's focus).
The creature's soulless body instantly withers or molders into dust.
Trapped in the gem, the evil soul undergoes a gradual transformation.
The soul reflects on past evils and slowly finds within itself a spark of goodness.
Over time, this spark grows into a burning fire.
After one year, the trapped creature's soul adopts the alignment of the spell's caster (lawful good, chaotic good, or neutral good).
Once the soul's penitence is complete, shattering the diamond reforms the creature's original body, returns the creature's soul to it, and transforms the whole into a sanctified creature (see Chapter 8: Monsters).
If the diamond is shattered before the soul has found penitence, the evil creature's body and soul are fully restored; the creature's state is just as it was before the spell was cast.
The creature retains the memory of having been trapped in the gem, and it regards the spell's caster as a hated enemy who must be destroyed at all costs.
The diamond receptacle has a hardness of 20 and 1 hit point.
Focus: A flawless diamond worth no less than 10,000 gp.
Sacrifice: 1 character level.