The Greatest Showman - Chapter 25: Indescribable

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates

This novel is also known as I Possessed a Demon Sovereign

Chen Luoyang felt that something was wrong with his transmigration. After transmigrating, he possessed the body of the highest expert in the world, the Master of the Demon Cult, addressed respectfully as the Demon Sovereign.

Generally, aren’t supreme experts the ones that leave behind a wisp of their soul behind and occupy a new body of some miserable low-level youngster then they go on a journey of revenge and make a comeback?!

Or perhaps it would be transmigrating into a miserable youngster’s body and obtaining a cheat slowly walking the road to becoming a God?

But why did his transmigration seem wrong?

Now my environment is full of big shots and I feel like I’m going to be exposed!

- Description from Novelupdates

As Orson read the novel written by the girlfriend who had left him, he gently remarked on how terrible the story was. But then, noticing a foul smell coming from the kitchen, he went to investigate. He realized there was some kind of gas leak. Already furious about being dumped, Orson became even angrier at the state of his kitchen, and in his rage, he hit the light switch with a powerful punch. Naturally, the explosion that followed killed him instantly, and Orson passed into the afterlife.After spending some time in limbo, he found himself reincarnated in an unfamiliar world. However, he quickly realized he had been reborn inside the cliché-filled novel written by his ex-girlfriend. As if that wasn’t enough, he had ended up in the body of Neonidas, a useless duke who was also the fiancé of the story's villainess.____There may be a bit too much swearing and slang in the first chapters, but it gets less afterwards.There will be no yuri, bl or ntr in Neonidas(MC) harem

An unnamed 34-year-old Japanese NEET is evicted from his home following his parents' death.

Upon some self-introspection, he concludes that his life was ultimately pointless.

Walking down a street he intercepts a speeding truck heading towards a group of teenagers, in an attempt to do something meaningful for once in his life he manages to pull one of them out of harm's way before getting himself in the way of the truck and dying.

Awakening in a baby's body, he realizes he has been reincarnated in a world of sword and sorcery.

He resolves to become successful in his new life, discarding his past identity for his new life as Rudeus Greyrat.