Eri Nakamura

Betrayed her classmates to the demons. Used her original darkness magic "Soul Bind" to manipulate countless numbers of dead puppet soldiers. After she obtain the power of apostle, she became more powerful than before and able to manipulate Kouki using soul bind even without killing him. Died using self destruct power which is 'last loyalty' after knowing Kouki no longer being manipulated by her. After she died, she have a face to face communication with Suzu telling her she would have been better if she met Suzu first instead of Kouki during her childhood time.

She has a very tragic past whereby her father died saving her from an accident and receiving her mom's hatred after her father's death. It was mentioned that her mother loved her only because she is her husband's daughter. After her father's demise, her mother betrayed her father by finding another male as her partner but Eri's stepfather was later imprisoned due to assaulting Eri. This resulted her mother again blaming her for seducing her new husband.

After the manipulating Kouki to her side, she behaves just like her mother by being clingy towards Kouki.

Personality
In the beginning, she is portrayed as a calm and quiet girl. But later on, it is shown that she is very cunning and willing to take advantage of classmates for her gain. She has a very deep obsession on Kouki to the point that she is willing to kill him to 'soul bind' him and make him her puppet. After obtaining the power of apostle, she grew wings.

Abilities
Necromancy:
 * Being able to use a dead corpse (even when severally damaged)
 * Being able to control multiple corpses at the same time