Demon Lord's Reincarnation

The remaining four of the seven heroes were confused by Ren's statement, on the other hand, Ren's companions immediately knew what was going to happen. They quickly spread out and took defensive stances. Ren could no longer hold it in and stomped his foot onto the ground causing the earth to shake.

Ren did not use mana nor Spirit Aura, that was simply his physical strength at full display, with his current strength this was enough to face most opponents. The moment he used mana or Spirit Aura, he might accidentally destroy a large portion of the continent, and worst of all he might not be able to enjoy this battle fully. 

The four heroes who were sensitive to the fluctuation of spiritual energy knew that Ren did not use any form of spiritual energy. They were already expecting Ren to be unreasonably strong, but this was beyond ridiculous. Just his physical strength alone was enough to shake the very ground they stood. He wasn't even releasing any mana nor bloodlust, but his mere presence was already causing them to feel extremely pressured. 

As they were still in a daze, Ren suddenly disappeared from their sights. They then saw something unexpected as Ren started attacking one of his comrades. It took them a few seconds to understand why Ren had done that.. 

'So he wasn't lying he really plans on fighting all of us!' Artemisia gritted her teeth feeling extremely frustrated. She felt like she was being looked down upon, and the worst part was she couldn't complain. Even though they were all-powerful individuals in their respective worlds, but in front of Ren, they were nothing. 

'This guy isn't the last boss, this guy is a f*cking hidden boss a raid boss. We need at least ten times the number of people present to win. I don't see anyway to win this, is this really game over?' Hayate gritted his teeth as he finally felt a tinge of fear creeping into him. 

...

Unaware that the remaining heroes were feeling hesitant, Ren was having a blast as he attacked Silika. He had summoned Snertal that had already ascended into a stronger spiritual weapon, that was already at the peak of the legendary rank as a weapon. 

Silika blocked Ren's strike with her scythe and wanted to push him away but to her surprise, Ren's physical power was stronger than it was the last time they sparred. Silika was blown away, but in her place, Valdel appeared and was ready to punch Ren.

As his fist was about to land on Ren's face, Valdel thought that Ren would dodge, but that didn't happen instead Ren headbutted Valdel's fist. Valdel who had imbued his fist with mana and attacked was the one that was blown away as his shoulder was dislocated. 

Ren's head was now bleeding but he didn't use his mana to heal it and continued fighting with the injury. Seeing the scene before them the four heroes were in awe of Ren. Unlike them who were having a difficult fight against Silika and the others, Ren who was holding back actually had the upper hand. They didn't know that except for Valdel all of Ren's companions weren't at their best state. 

Even though they didn't want to accept it, the heroes knew that the only way to beat Ren was if they join forces with Silika and the others. It was at that moment the heroes joined the battle and attacked Ren from all sides. 

...

Ren who was being bombarded with spells, and was being attacked from all angles was filled with glee. He wasn't using his mana nor his Spirit Aura to defend his body from the attacks. He was receiving everything with nothing but his flesh and blood.

It has been such a long time since he had received such damage in a fight that he was ecstatic. He once again reaffirmed that only battle could bring him such joy. Power, family, treasures, immortality no matter what it was, to Ren, to the Strongest Mortal Soul, nothing could compare to his love for battle. He was entranced by the desperate struggle between opponents as they try to emerge victorious in battle, the excitement of feeling his very essence being burned away in the heat of battle. 

It was like he was born just for the sake of battle, for the sake of becoming stronger than anything else. Even though he had gained a lot and learned how precious his friends and family were, deep down he knew that he could never fully change himself. Ren who was now bleeding all over wiped away the blood on his face and shook his head. He started to discard all the unnecessary thoughts and focused fully on the battle. 

Everyone noticed the sudden change in Ren. There was no dramatic change in his appearance, nor did he start using any spiritual energy, but everyone understood that Ren had finally gotten a bit serious. 

...

Xia who saw Ren's bloody figure, suddenly had the naive thought that they could actually win. For as long as Ren continued using nothing but his physical strength to fight, then they could win against the monster. Yet that naive thought of hers was immediately shattered.

She could not explain it but despite Ren's numerous injuries, and his reluctance to use any spiritual energy, Xia suddenly felt an unusual pressure emanating from him.

Ren then started charging at the nearest person, and unlike before he no longer bothered to dodge the attacks. 

Ren started to attack more ferociously than before, and what made the entire scene creepier was that he continued to smile that vicious smile of his. You could no longer see much of his face at it was covered with his own blood, and even his eyes were no longer clear to see, yet that smile of his was there for all to see. 

...

Despite their struggles, in the end, Ren had won and all others had fallen. To top it off, except for the knights' Ren had not taken a single life of any of the heroes.