Dr. Aleister

Dr. Aleister is Serenity's father and creator of the Demons' Score.

Six months prior to the events of the game, he was approached by David with a mysterious ancient book that contained musical scores composed by a demon. They discover that the music was for summoning and controlling various kinds of demons, as well as open a gateway to Hell.

Aleister saw that he could create a new world and become a god using this power. So he worked together with David in order to decode the book. However, he needed a messiah to wield the Demons' Score on his behalf, so he created Serenity during that time and gave her false memories of mother and father. He then sent her to Bosten College and continued his work on the book. After performing a decoding test, David's soul was blasted out of his body. However, Aleister was able to complete the app before being fused with Satan.

He appears in front of Serenity during the final fight and tries to hold back Satan's power. He says his goodbyes to Serenity before fusing with the demon and is destroyed by Serenity's full power.

After the fight, Aleister's disembodied soul emerged from Serenity's phone informing her of her success. However, Serenity rejects Aleister's plan and destroys, using the Demons' Score for her own purpose.