Demon Lord's Reincarnation

In the eternal forest where the elves live, a sudden massive burst of mana started to envelop and encroach the whole forest. If that wasn't bad enough after the massive burst of mana came a blood-curdling killing intent. The killing intent was so terrifying it made even the bravest weak in the knees.

Those that were farther away from the source of the mana burst and killing intent were less affected and only felt a bit dizzy. The unlucky ones who were near the source were the elders and the elite guard. They were able to withstand the pressure but it was taking everything they got to remain conscious. Some of the weaker ones even started puking and crying. 

On the other hand, the elven children who were supposedly too weak to resist the power of the mana burst were for some reason unaffected by everything that was going on. The person who had released that overwhelming mana burst and frightening killing intent was able to control his mana so precisely that he was able to avoid affecting the children. Even his killing intent was so accurate that it only affected those he wanted to be affected. 

...

The Elven Queen Kara who was sitting in front of Ren was looking at Ren in dread. Ren who was releasing such a horrifying killing intent coupled with an overpowering mana burst made the Elven Queen sweat profusely. It took everything in her power to not succumb to the dear as she was trying her best to stop her body from trembling. She could hardly breathe as she struggled to stay conscious. 

Leila who was sitting beside Ren couldn't feel the mana burst nor the killing intent, but she knew that Ren must've done something to make Kara act this way. She actually felt a bit sorry for the Elven Queen who clearly had no choice but, to tell the truth, no matter how bad.

"Are you telling me that I can't take her back?" Ren's voice was ice-cold as he looked at Kara. He stopped emitting killing intent and restrained his mana so that Kara can respond properly. 

Once she was released from that terrifying pressure Kara felt like a person who was drowning that was finally given air. She couldn't help herself but pant as she looked at Ren with even more fear than she initially showed. 

The knowledge passed down by the previous Elven Queens did not skimp in telling her that the strongest mortal soul was a fearful existence. She already tried to mentally prepare herself before Ren came to the forest, but experiencing that aura up close was beyond anything she could imagine. 

Kara as the Queen of the Elves had once met a young Golden Dragon, who had also threatened the elves by wanting to occupy the Eternal Forest. Of course, she didn't agree and with the help of Tsukiko, they were able to repel the mighty dragon. Yet even that time paled in comparison to this encounter with the strongest mortal soul. 

At least with the young dragon, they had a chance of surviving, but against Ren, they could do nothing but accept their fates once he decides to annihilate them. 

"I'm going to ask you again, are you telling me that I can't take her back?" When Kara heard Ren's voice she tried her best to gather her strength to speak out an answer. 

"I... I wouldn't dare... If Sir Ren wishes to take the protector we are powerless to do anything. It's just that the protector cannot stay away from the tree for a long period of time." Kara choked and stammered a bit as she answered.

"Then what will happen if I just destroy the tree?" When Kara heard Ren's response she grew even more nervous. 

"I don't think that would be a good idea." 

"Do you think I can't cut the tree down?" 

"No sir, that's not what I meant. I do not doubt your strength. If it were anyone else that said they would cut the tree of life down, I would've thought they were insane, but if Sir Ren says it then I would believe it full-heartedly."

"Then why don't you think it's not a good idea?... Oh, I see... If Tsukiko dies the tree will only be damaged a bit and will then choose the next protector. So what happens when the tree itself dies?" Even though Ren could already guess the answer to his question, he wanted to be sure.

"As I said before if the tree of life dies all beings on the mortal realm will slowly lose mana, and the beings that are composed of mana will cease to exist. Aside from that, the protector of the tree who shares her life with the tree will die with it." 

Hearing the answer he expected made Ren frown. He then closed his eyes and calmed himself down before asking another question.

"Then do you know of a way to sever the link between the tree and its protector?" 

"I do not know, and even if I do I don't think it would be a good idea to attempt such a thing. If you do succeed in severing the link between Lady Tsukiko and the tree of life, Lady Tsukiko would return to her former state before she was healed and die." 

'I can deal with her injury of that time, but I need some way to sever the link between her and the tree.' Ren remained silent for a few seconds. Ren then stood up from the tree branch and sat crossed legged in the corner of the house. 

"Leila I'm going to do something, in the meanwhile I want you to protect my body." Leila without questioning what Ren was about to do nodded her head and stood in front of him. 

"There's no need to worry about your safety. No one in the Eternal forest would dare attack you. In fact, they will do their best to protect you from all harm." Hearing what Kara said Ren looked at her for a while and didn't bother to respond as he went into a meditative state. 

If he couldn't find the answer from the elves, he would ask the people in his soul realm, his past incarnations. Surely one of those powerful beings would know of some way to deal with his current problem.