He is Lovestruck in the Revenge - Chapter 212 - 205 Fell asleep again and dumped it (first update)

After dying prematurely from an incurable disease, Yuka Hikano finds himself in a mysterious realm filled with endless doors, each concealing divine gifts from powerful deities. He is not alone—others who have met the same fate of death stand beside him, unaware of the trials that await.They are put through various tests and eventually transmigrated into different worlds. But these worlds are nothing like the Earth they once knew.For Yuka, however, this apocalyptic world feels eerily familiar. It is a realm of endless war, devastation, and chaos—a world he once played in a game. Certainly not the kind of place one would wish to be reborn into.From infancy to adulthood, he must gather strength, knowledge, and allies to survive the horrors that lurk ahead. But when he awakens a system granting him a power beyond imagination, he soon realizes that blessings can also be curses.[You have gained Infinite Mana.]Infinite Mana...?What could possibly go wrong?

A young man who had longed for stories of good and evil since childhood lost his life in a tragic accident and was reincarnated as a boy named Chrono Mak in another world.

He learned that in this other world, there is magic and witchcraft, and depending on how you train them, you can become as strong as you want to be, so he decided to become the strongest demon king in order to recreate the story of justice and evil he once dreamed of.

mc gets transmigrated to Fallout New Vegas with the merchant system. let the questionable adventure begin.

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates