Devil Surprised says "What are u made of kid" it got trapped inside Haruto..
It's Orginal plan was to revive itself by taking Haruto 's body but he was not feeling any emotions of being scared so it backfired..
But the clause still remains..
He found the contract paper and it says to activate power you need to drink a DEVIL BLOOD or devil's blood.
He didn't knew a devil was approaching at that time he was suddenly ambushed...
He was going to die but he suddenly saw the abandament devil's blood. He ran past the new devil which was Oil Devil and licks the abandament devil's blood.
His physical appearance changed. His skin turned pale white his veins were visible but not red black in colour His eyes colour changed to Crimson Red he was looking alomost like the Crimson Devil.
He fought the Oil Devil because he doesn't know how to use skill he went for Crimson Devil Terrain Expansion.
(Terrain is just a hollow space which if activated by humans can absorb devil's life or can implement never regneratblte damage while devils can show human a torturing memory or kill them using their desire)
Haruto uses the Terrain Expansion Crimson Eclipse
It takes the Oil Devil into the Terrain and absorbs it's life out of it and kills it..
Because he used the Terrain it was an exclusive power it activated the clause and so Haruto loses a Memory How his Mother's voice was...
He suddenly feels like a glass broken inside his mind..
Then he realises he can't remember how his mother's voice was he is feeling pathetic and starts to feel despair for forgetting his mother's voice and gets scared of using the Crimson Devil's ultimate power Terrain Expansion.
It is then shown that a Guy With white hair who is wearing a white dress and has a cross symbol at back of the cloth sees Haruto crying in the middle of the massacre and he notices two devil's lying beside him and is now going to confront Haruto.....