Spiritual Surgery

Spiritual Surgery (心霊手術 shinrei shujutsu) is an experiment conducted by Martuba's Tomb.

Patients
The people below were confirmed to have spiritual surgery done on them.
 * Naho - Restored body into a healthy shape.
 * Satsuki Nekoma and Harue Mizuhara - Combined into Satsuki Mizuhara.

Naho
The surgery, performed by Magari, restored Naho's body after Magari purposely kicked Naho and a swinging giant axe cut open her abdomen, which result in massive blood loss and scattered organs.

Satsuki Mizuhara
The surgery enables Satsuki to assume a "monster form". In this form, Satsuki splits her head into eight equal parts, revealing a giant mouth with rows of sharp teeth and jaws strong enough to tear apart and devour one's head within seconds. The surgery did not only affect her physique, but also affected her personality. Satsuki inherited the personality of Harue.

The "monster form" of Satsuki Mizuhara is sealed and controlled by Magari with Synapse. When the control breaks by other means, Satsuki will go berserk and devour anyone within her line of sight, unable to suppress her appetite.