Demon Lord's Reincarnation

As Ren was having the time of his life fighting the neverending torrent of enemies, he hasn't noticed that he was sustaining damage, though they were just some tiny scratches. he was slowly but surely accumulating wounds. It was then Kim Chul arrived to provide assistance. He appeared behind Ren and attacked the knight who was about to stab Ren at the back. 

"Ren, thank you for telling me about the truth. So as thanks please allow me to help you in th-" Kim Chul wasn't able to finish what he was going to say as he was blown away by a punch. Kim Chul quickly regained his balance and looked at his attacker. The one who punched him was none other than the person he wanted to help. 

"Don't you dare get in the way of my fun, hero! Just stay at the side and protect those that you must protect. But never under any circumstances think that I'm one of those people that need protecting. So get back and watch at the side, if you continue to be in my way then I will slay you alongside everyone else!" 

Ren then started to emit such an intense bloodlust that the wyverns and horses of the knights were going crazy. 

Hearing Ren's threat as well as feeling that overwhelming bloodlust of his, Kim Chul wasn't scared, but he looked at the anger in Ren's eyes and sighed. Kim Chul then backed away heading towards the place where he hid the citizens of the lower district. As he was retreating he saw the anger in Ren's eyes fading and was once again replaced with glittering excitement. 

"Now let's get back to the fun!" 

...

Baldur was watching from one of the airships and saw the horrific battle unfold. No, what was happening before him could not even be called a battle, that was a simple one-sided massacre. Though they were able to somehow put some scratches on Ren's body that was all the damage they could manage, despite using everything they had. On the other hand, Ren had effectively destroyed around a third of their army. 

The wyvern knights were just used as things for blocking and throwing. The mage unit that was down there could not even get past Ren's mana barrier. 

"Switch to anti-mage tactics, now!" 

Even though Baldur already knew that for some reason Ren was not bothered by the mana dispersers he still needed to give out the order, since if they continued without changing something Ren would continue to massacre them. 

...

Ren was able to immediately notice the smoke that stops the flow of mana as this was already the third time he felt it. The moment he sensed the mana flow stopping Ren quickly started using Spirit Aura. While using Spirit Aura a lot of his techniques that needed the use of mana would become unavailable, but that wasn't really that much of a problem for him, in fact, that was something he welcomed. 

Ren started using the steel wires hidden in his gauntlets, while the knights were now using those rifles that fired metal. Ren was able to use his steel wires like thin blades that cut anything that comes near him, effectively cutting the bullets bursting out of the rifles. Ren then started waving around his hands as if he were dancing. As he passes by the knights with elegant movements, those same knights became sliced meat. 

The knights tried to surround Ren with their giant shields to somehow stop him from moving, yet Ren who using the steel wires coupled with Spirit Aura was able to slice through their defense like it was paper. 

It was a terrifying sight to behold, but despite them being absolutely annihilated the knights of the Temple of Light never backed down and continued to attack Ren. Even in such a dire situation the knights never doubted their victory, for as long as their beloved Goddess lives, then victory will always be on their side. Those thoughts filled their minds as they willingly gave up their lives for the sake of the Temple, for the sake of their Goddess.

Watching the fearless knights charge and die for the sake of their Goddess was such an inspirational sight for Baldur. The head priest of the Temple of Light could not help but shed tears of blood for the fallen warriors of the Temple. 

'May all of you brave and courageous knights find your solace by our beloved Goddess's side.' Once he was done praying for the lost souls of his fallen comrades, the head priest spoke to the commander standing beside him.

"Are the preparations not yet finished?"

"Due to the unexpected deaths at the beginning, we weren't able to keep up. We haven't finished it yet. It might take a few more minutes." Hearing the commander's answer Baldur gnashed his teeth in frustration. 

"Damn it! Don't you see our fine comrades down there being killed by that heretic?! For every second that we delay, more and more of our comrades will fall."

"We will speed up the preparations!" 

...

As Ren continued to kill the knights of the Temple of Light, he suddenly felt some kind of pressure coming from above. The feeling he got was the same as when he fought the Goddess of Light. 

'Is she about to descend?' Ren quickly took out Snertal as he looked above his head. He then heard the irritating voice of the head priest. 

"Heretic, you have killed thousands of our brave comrades, but even then we will not falter. It is time for you to receive divine punishment. This spell was something granted to us by our beloved Goddess so receive it well, and DIE! [Heaven's Light]!" 

A giant magic circle appeared on the clouds above the city. Ren knew that even if he ran at full power he wouldn't be able to escape the range of that attack. He was also unable to teleport due to the mana flow being disrupted. This was an extremely grim situation for him, but it just made him smile even more. Ren gathered every bit of his Spirit Aura and coated himself with it. 

A gigantic beam of light descended upon Ren, obliterating everything from the buildings to even the mana in the air. Yet for some reason the light did not affect the knights that surrounded him not a single bit. As if able to read his mind, the head priest spoke. 

"This is a divine spell granted by our Goddess, those that are under her, will never be damaged by its warm light. Now be gone from this world you damn heretic!" 

...

'Now this is turning out to be even more exciting than I thought!' As Ren was getting ready to initiate a counter move, he suddenly heard someone's voice. It was the voice of a woman, and it sounded extremely familiar to him. 

"Kukuku, what a hideous light this is. Such a thing isn't worthy to be in our reunion." The moment the voice spoke those words, the beam of light scattered and disappeared into nothingness. After that, even though it was midday the surrounding area suddenly darkened. A silver moon appeared above the clouds, and basking in the moonlight was an otherworldly beauty floating among the clouds. 

She had long wavy black hair that cascaded down her back towards her hips. She had an enchanting figure, that could make any man look her way. She was wearing a white blouse that showed a bit of her chest, and a short red skirt that emphasized her thighs and long legs. She was also wearing a black kimono over her blouse which only covered her arms and a bit of her back.

As Ren looked at the otherworldly beauty his birthmark that was shaped in a full moon started to shine brightly, it was at that moment the ruby red eyes of the beauty stared at Ren, the beauty then smiled a bewitching smile. Her melodious voice tickled Ren's ears. 

"It has been ages, my love, I Tsukiyomi the eternal moon has once again returned to your side."