Identity theft - How to become doppelganger

Doppelgangers are not a race. They don't born the way they are. Behind a doppelganger there is torture, cruelty and black spells.

To become a doppelganger wizard must first prepare a mask of human face. It needs ritual sacrifice to detach the face from a victim. Once the face is detached the wizard makes a mask of it. He then prepares another spell and must pass as the victim in front of people who know the victim well. Then the mask merges with wizard's face.

Wizard must repeat the above 10 times. After 10th time he has made the rituals and spells and has passed as a victim he transforms into a doppelganger.