The Ambitions to Conquer the Official Career - Chapter 613: Something’s Different

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

Takahiro Nao, a 25-year-old burdened by crushing debt and driven solely by his love for his struggling family, meets a tragic end—until a mysterious Goddess of Benevolence offers him a second chance: reincarnated in another world, and his efforts there will provide for his family back on Earth. Awakening in the body of Naoki von Blackmore, a disgraced “Failed Hero,” Nao is thrust into a realm of sword and magic, monsters, and war, tasked with the impossible mission of defeating the Demon King. With newfound powers, a shadowy past, and the weight of two worlds on his shoulders, he must battle not only relentless enemies but fate itself. Blending emotional depth, thrilling action, moments of humor, and a spark of romance, this gripping isekai adventure asks: how far would you go—and what would you sacrifice—for the people you love?

Following a brutal and tortured death, a former assassin, known only by his codename Kuro, is given the opportunity to reincarnate in another world, a world with magic and monsters. Armed with an unrivaled healing factor and an inhumane pain threshold, Kuro opts to go for a reckless direct approach in this world instead of a stealthy and cautious one, and as a result, slowly gains attention bit by bit.

Having previously been a loner in his old life, he interacts and befriends people for the first time in his existence, however, his blunt nature also sees him making just as many enemies, both big and small. By combining his old assassin skills with the magic powers of this world, along with his high resistance to pain and rapid regeneration, he doesn't take long to establish himself as a formidable force in this world.

Initially, Kuro only faces minor threats, like weaker monsters and bandits. But before too long, the threats slowly but surely become more and more severe…from Zombies to a bloodthirsty empire to Vampires and Demons, and even divine beings…however, as the enemies he faces grow stronger, so does Kuro, gaining rare powers that have never or rarely ever been seen in this world…