The World of Otome Games is Tough For Mobs - Volume 7, Chapter 10 “The Most Dangerous Man”

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…

My biggest achievement is not the first person in the entertainment circle, nor the teacher of all people, nor my wealth and status. My proudest achievement is that I live the way I want, not just Live the look that others want – Ye Guang.

- Description from Novelupdates

Klein’s greatest wish is to transmigrate to another world and live life in an isekai, just like in anime, manga and novels. However, fate is on his side and the typical truck that the main characters always carry in isekai runs over Klein. But, to his bad luck, he lived a few more days in the hospital and, just on the day he died, Klein heard a ⟨⟨-DING-⟩⟩ that he knew it meant. That was the day of his death, but also the beginning of his adventure into another world.