Past Life Returner - Side Story 45: New Year(1) - Chief Mourner Kim Jin-Cheol

True evil needs no reason to exist.

“All living creatures must die, but I wont. ”

Once known as the most talented and knowledgeable scholar/philosopher across three continents, he basked in the praise and reverence of those around him. However, tragedy struck one fateful night when he bore witness to the cold-blooded murder of his entire family. Driven to madness, he embarked upon the path of power, the path of negative energy, and thus, The Great Demon, Badur, was born.

In a single day, a mountain of corpses were stacked, many of which fell to his blade. However, during his final pursuit of revenge, he met his untimely demise. His soul was extracted and cast into the void, where it would endure eternal suffering.

However, his jouney would not end here……

“What do you desire?”

A grotesque creature floating in the void asked while staring at the bruised and beaten soul of a young man.

[Ding!! Host has received Void grade Treasure]

[Ding!! Goal has been set : Attain True immortality]

A new lease at life is presented

A deal with a Demon filled with resentment

A new journey, a new Dawn

With that the great Demon, Badur is reborn

ps: the book won't progress the way other novels have been progressing. if you don't like a unique development then maybe this isn't the book for you.

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

After putting a suggestion to add a mercenary in a bad Murim novel he read, Leo would finish a mission with his NPCs before sleeping. Or so he planned. For some reason, he was transported into the said novel as the extra mercenary added by the author. His loyal NPCs, a yandere secretary, a happy-go-lucky assassin, a sexy puppeteer, and two weapon maniac guys start to become sentient. He lead his mercenary band ’Hallowed Insects’ toward an an unprecedented future in a Murim most turbulent era while enjoying his time. Fortunately, they still have their futuristic equipment with them. Tang Clan have a Poison Dagger, they have a Photon Sword. Shaolin Sect has a Qi Blast, they have a Railgun. And of course... “How much are you willing to pay to employ us? By the way, Demon Sect pay us 50,000 Golds to join their side in the upcoming war.” ... he always sided with the highest bidder.

This is a story of an ordinary boy gaining unusual powers from his nightmares… It all started when Lin Sheng experienced something strange on what he thought was just another normal day. He begins to have recurring dreams that lead him on an incredible journey of discovery as he encounters spine-chilling monsters and elusive secrets.

- Description from Novelupdates