Demon Lord's Reincarnation

Every single being on the battlefield was shaken to their very core as an incredibly massive amount of mana and bloodlust encroached them. Even the undead that no longer had any human emotions have stopped their assault, as their bodies were unable to move properly because of the sheer power of the mana that was felt throughout the battlefield.

On the humans' side, even the courageous Regalcrags were trembling in the face of such overwhelming, suffocating bloodlust. Galius who was already full of wounds and was near death couldn't help but laugh a very hearty laugh. The tides of battle were going to finally change.

Still, among everyone present, it was the two holy maidens that were the most surprised by this feeling they were having. The two holy maidens have encountered many powerful beings even so-called messengers of Gods, they have met most of the strong humans within the continent, from the olden masters to the young geniuses. Yet never had they felt such a powerful burst of mana that felt like it would devour anything and everything. Never have they felt such a spine chilling bloodlust that could make even the bravest of men cower, that could make every fiber of their being wish to escape from this place. 

On the other hand, Iselv and Kithra were smiling from ear to ear as they felt such overwhelming pressure. They knew that this overpowering force can only come from one person they knew. Now that he was here, they felt like victory was all but assured. 

...

Valdel who was fighting one of the undead dragons was able to feel the familiar fluctuation of mana and couldn't help but smile. Even though his best friend kept on saying he didn't want to be a hero, and sometimes even showed extreme contempt to the very word itself, but there's no denying his timing was like a hero's. Always coming when all hope is lost and bringing with him that ray of hope, that assures people that everything will be alright.

...

Lara who was evading each attack of the undead dragon she was facing, was getting excited. The person she waited for was finally here. The moment she felt that suffocating bloodlust she felt relieved.

'I hope that Ren's able to see me fight this undead dragon. I need to do my best and finish of this giant skeleton lizard with style. Not only should I finish with style, but I need to end this fast, but not too fast that Ren won't see my cool side.' 

Though it was undead and was not even half as powerful as it was when it was alive, what Lara was facing was still an adult dragon. Yet even as she faced her strongest opponent yet, Lara was only thinking about impressing Ren. 

...

The Elder Lich who was watching at the back of his army was surprised to feel this pressure. The last time he met Ren he knew that this human was something else, but he was still surprised to feel this. The amount of mana Ren was emitting was way above the last time they met. 

Not only that, but the bloodlust he was emitting was something only beings that have massacred thousands upon thousands could emit. This was both surprising and confusing, how could a human that wasn't even twenty be able to emit such bloodlust? 

If that wasn't enough Ren was emitting something aside from mana and bloodlust. It felt like a new kind of power. Feeling these things from but a single human, made the elder lich cackle in delight. 

'You are even more delightful than I expected... Show it to me human! Let me see the depths of your power!'

...

From above the sky like a bolt of lightning Ren landed in front of Hilda's body. The undead monsters that were near Hilda have crumbled with the sheer force of mana Ren was unleashing onto them. 

Ren looked at Hilda's body and injected her with a bit of his Spirit Aura. He then whispered something in Hilda's ears. The unconscious maiden whose heart was beating slowly was obviously unable to respond.   

Ren who was in the middle of the battlefield turned blurry and in front of everyone's eyes disappeared. In the next moment, he reappeared on the walls of Grenton. He approached one of the remaining knights and handed Hilda. 

"Protect this woman with your life. If you fail then your life is forfeit." The knight unable to utter a single word simply nodded his head. Ren who was surveying the entire battlefield concluded that victory was unreachable in their current states. 

Still, that didn't make Ren worried instead it made him laugh. His laugh echoed throughout the battlefield. 

"HAHAHAHAHAHA! I was going to come and find you to finish our fight. But how kind of you Alfred to come here with your whole army at hand! Surely this battle with you and your army will bring me endless excitement! Come master of the undead! Come face me so that you may meet your eternal demise!"

Ren's voice wasn't that loud but everyone present was able to hear what he said. This made the Elder Lich curious wanting to know how Ren was going to achieve what he proclaimed. It was then Ren took out something from his pocket, it was an object wrapped in a weird cloth.

'Hmph, who knew that a horn from my traitorous son, would help me today.' Ren then stabbed the horn onto his lower abdomen. A magic circle that he drew on himself started to activate as it absorbed the horn. 

Ren then extended his hand and a dark orb appeared. Once the darkness cleared what was shown was the heart of a young dragon, known by most of the people of the land as the dungeon core. 

Ren with the dungeon core at hand started eating it. Everyone who was watching Ren was dumbfounded by the sight. But before they could comprehend what just happened, the mana Ren was emitting had doubled. 

If it was already suffocating before, with the strength of the mana Ren was emitting right now, actually made some of the people near him faint. Even the holy maidens who were watching at the side could barely stay conscious. Though they haven't heard the name of the person before them, the two can pretty much guess that this was the friend Valdel was praising endlessly. 

'This man is supposed to be even younger than Valdel?...' Both Rachel and Natasha had the same thoughts as they were trying their hardest to stay conscious. 

...

Alfred who was watching at the distance was surprised to see Ren have a demon lord's horn and even a young dragon's heart. But what surprised him, even more, was the fact that Ren was able to use these two objects to boost his power. 

Alfred already did some research regarding the young dragon's heart, a.k.a the dungeon core. He was sure there was no possible way for a human to use the dungeon core as a power source for oneself. Yet here was a person that actually did it. 

'Now I'm even more sure Ren is the key. He is the key to advance my research to new heights. With his body at hand, I might be able to finally solve the mystery of true immortality.'