Demon Lord's Reincarnation

The man holding the weird-looking sword was looking at Ren with a murderous gaze. In response, Ren simply showed his trademark smile. 

"What do you want? Why did you kill my men?" The man presumably the Marquis spoke to Ren.

"You killed one of my men, and you're asking me why I'm here?" Ren answered happily as he was brimming with excitement. 

"Oh, so you're the one who sent that assassin to kill me. So what do you want? Did you kill my men because I killed one of yours? But you were the one who struck first, I just retaliated in self-defense."

"That's just part of the reason why I came here. The other reason that made me come here was because of an assassin that uses curses. Someone in your family hired him to kill the whole Kirche family, and I wanna know why." 

'Something like that was happening under my nose. Did it happen before my soul got transferred over? Who was the idiot that did it?' While the Marquis was thinking about who could possibly do something behind his back, Ren took a sword from one of the knights present and without the Marquis noticing he was able to appear in front of him. 

In the past few days as they were searching for where the Marquis was hiding, Ren was practicing on how to use Spirit Aura better. So now his usage of Spirit Aura was less wasteful than the first time he tried using it. 

He was still not as proficient in using it like mana, but it was still the better choice when it came to physical augmentation. 

...

The Marquis wasn't that shocked by the instant movement Ren displayed, what shocked him the most was that Ren didn't use mana to do that move, instead he used Ki. Ever since he took over the body of Lance Resteti, he has never seen anyone use Ki before. Most of the residents in this world use mana, so it was truly surprising to see someone who can utilize Ki in this world to such a degree. 

While Lance was still stunned Ren was looking at Lance's sword intrigued. He then asked Lance a question. 

"So what kind of transmigrator are you? Are you the type that level-ups, claiming that this world is a game? Are you the type that has read the events of this world in a novel, claiming that there is some kind of protagonist? Are you perhaps the type that claims to be an immortal from some high and mighty clan? Are you perhaps just some poor sap that got unlucky and came into this world by chance? Or perhaps you're a different kind of transmigrator? So tell me which are you?" 

Lance didn't bother to answer Ren and simply swung his sword trying to kill the intruder. Ren easily dodged his attack. He then gathered his ki and started to move even faster, in response to this Ren also gathered his Ki and blocked the incoming sword slash.

"How are you able to utilize Ki, are you the same as me?"

"Ki? Oh, do you mean Spirit Aura? Well, why should I bother answering your question if you don't want to answer mine?" While the two were in a deadlock Ren suddenly kicked Lance's abdomen blowing him away. Lance was blown a few feet away before he was able to stabilize his balance. 

Lance who was blown away started to concentrate harder. At first, he was still slightly curious as to how Ren knew that he was someone who took over Lance's dead body, he was also curious about Ren's usage of Ki. But now he decided not to bother anymore since Ren was obviously trying to kill him from the getgo by sending that assassin, then why should he bother holding a conversation with the guy. 

Lance then changed his stance and gathered his Ki onto his sword. When Ren saw what Lance was doing, he couldn't help it but his smile grew even more vicious-looking than normal. Lance's Ki then started to materialize around him and several giant swords started to float around him. Lance then did a piercing motion which made all the swords that floated around him fly towards Ren's direction at blinding speed. 

It was such a big move that you wouldn't expect Lance to use it in such an enclosed space like inside a cave, but for some reason, the damage was only focused on Ren's area. 

"That's a pretty cool technique, but you didn't scream the name of your technique, meaning your not the type that would call this world a game." Lance was surprised to hear Ren's voice behind him. By reflex Lance slashed his sword behind him, but as expected Ren was able to dodge with minimal movement. 

Lance then made the large swords that floated around him smaller, once he did that he started to attack Ren with his sword at hand as well as with the floating swords. Even with several swords hacking away at him and with such coordination, Ren was still easily able to dodge each one. 

Lance who saw how easily Ren was evading his sword dance made him grit his teeth. If this was back in his prime he would've been able to summon a thousand blades. 

After a short time of dodging, Ren started to counterattack. He joyfully swung his sword around which frustrated Lance as Ren was easily able to push him. 

Silika who was watching at the side was also smiling, seeing how happy Ren was, she now fully understood how frustrated he was about the fight with Nezzard. 

...

After several bouts, Lance was now sure that no matter what he did in his current condition he won't be able to so much as scratch Ren. He then distanced himself from Ren, who just stood there waiting for Lance to do whatever he wanted. Seeing how confident Ren was in victory just irked Lance even more. Every time Lance used a new move Ren would happily receive it. 

"So what else do you have for me?" Hearing Ren's question Lance took out a shining oddly shaped orb. Ren and even Silika didn't know what that was. Both of them especially Silika have lived a very long time and seen a lot of artifacts but this was the first time they saw something like that. 

"I now know that my current self is no match for you. But with this artifact, I'll be able to show you what true power is like. With this artifact, I can make my soul materialize and form an actual body. Everyone within fifty meters of me would have their souls materialize as well. Normally this would only serve with making a doppelganger for both of us, but for me it's different. As you are already aware my soul that is residing in the body of Lance Resteti is different. For I am Wang Lin the mighty heaven's sword! The greatest swordsman under the heavens!" 

Ren wasn't all the impressed by Lance's title as heaven's sword, what caught his interest was the use of the artifact he was holding. If Lance uses that artifact things would get boring real fast.

"I'm going to warn you right now if you use that artifact the advantage you think you'll have won't happen. Instead, you will be horribly outclassed that I kinda feel sorry for you."  

Lance couldn't understand any of Ren's nonsensical babble, and without hesitation activated the artifact.