The time has finally come for me to put in a mature content warning. The source material kind of made it hard not to, but I'm putting this in just in case you decided to skip all smut scenes in the manga (try it while retaining an idea of the plot, it's hard!) So I'll put bracketed [ ] warnings before and after mature content for further warning, I'll even put them in bold for you to see clearly. You've been warned!

Havi saw Vald glancing back at Haleceles and something made him worried about the demon coming out of Vald. He didn't have any memories that would help him in this situation but somehow he just knew that Vald was in danger of losing control.

"Come with me," he said, grabbing the student's arm and pulling him in the direction of his office. Thankfully it wasn't far away, because by the time they got there Vald's face was beginning to show the black marks that meant the demon was taking over.

"Vald?" Havi asked. "Vald, are you alright?"

"I don't know…" Vald replied. He closed his eyes and appeared to be in pain, breathing heavily and sweat beading on his forehead. "Why…? That professor's name…"

Havi knew that Haleceles was one of the original sorcerers who performed the ceremony on Vald's ancestor, but why the demon would want to attack him was beyond Havi's comprehension. A sense of déjà vu made Havi think that this have happened before and he racked his brains for any meeting between his student's former self and his master. Unfortunately he only recalled one incident where Havi had to stop his master from killing Demon Vald, who then fled not long after being saved.

While Havi was racking his brain, Vald was getting worse. Havi glanced up to see the student doubled over in pain, clutching at his chest and gasping for air. His skin had gotten darker and he was now covered in black marks, making it clear that he was barely hanging onto consciousness.

Acting on a hunch, Havi pushed Vald down on his chair and pulled out two sets of handcuffs that he had bought after the murder on campus. He handcuffed Vald, now completely gone and replaced with the demon, to his chair and succeeded in stopped the student from leaving.

"I'm afraid I can't let you leave, Vald," Havi said calmly to the demon.

Demon Vald snarled at him and growled threateningly.

"How did I restrain you before?" Havi asked allowed to himself. "I don't recall having to rely on anything other than my own strength, but I can hardly stop you with magic this time around."

Demon Vald bite at him and smirked. He pulled against the restraints and growled angrily at Havi.

"Well don't blame me for my poor memory," Havi replied. "It's not like you can remember either, well at least normal Vald. I don't suppose you remember me at all either?" He leaned closer to the demon who tried to slash at him but failed. "I guess that's a no."

He observed the tortured student a bit longer. His chair was taking intense punishment, the demon figuring out how to slam down on it and make it fracture and crack. Other than that it was obvious of the intense power radiating from the demon.

"You're more potent than any restorative," Havi whispered to himself, the words sounding like an echo across time. "Well isn't that just so crude," he commented louder as memories came to him in vague emotions instead of vivid recollections. The emotions were full of passion, of the most intimate nature.

[Mature warning starting now. If you don't want to read then skip to the next message in brackets.]

"I seem to have no other choice," he grumbled, "but I won't do as much as my previous life did. Just because he's a demon now doesn't mean he's not still my student."

He knelt down in front of the demon who eyed him suspiciously.

"Relax," he smirked and moved to be between the demon's legs. "This won't hurt at all."

He reached forward and touched the slight bulge in the student's pants. His eyes widened slightly. So he really is as passionate as before, Havi thought. Of course not everything can be the same.

Havi unzipped the demon's jeans and pulled them down with his boxers, but just far enough that they would be out of the way and not off completely. Vald already had a half-hard erection which twitched as soon as Havi touched it with his hands.

Havi leaned forward and licked the shaft, hearing a pleasure growl come from the demon hovering over him. Despite not having clear memories from his past life for any of this, the professor still felt that he knew this body intimately and knew just how to touch and pleasure the younger man to get him to stop resisting.

The demon's growls turned into grunts and moans, getting closer each second. Havi licked the head and sucked on it, knowing that would give the other man the most pleasure. After one such suck the demon released into Havi's mouth with an extended groan of pleasure.

Havi swallowed the load and then pulled away from the spent form. As he watched, the student's skin paled until it returned to normal and the marks completely disappeared from his face. His head hung limp, the student falling unconscious after the demon ate up so much of his energy.

[Mature content over, now will be rated T max.]

Havi pulled up Vald's pants and boxers, making sure all evidence was gone. He also felt an intense power flood through his body, filling him with energy and what he knew to be magic. Now he was able to recall his previous life beginning a physical relationship with the demon to use up the demon's intense energy that caused the prince's body so much strain, and also to rejuvenate his own stores of magical energy.

"You are still quite interesting," Havi said quietly while undoing the handcuffs and returning them to his desk, "my selfish prince."