You are all bad women! Don't come over! - Chapter 25 - 24 Brother, Brother (Vote for me!)

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

In a world where the boundaries between dimensions are thinning, a young man named Kael Ardent is thrust into the Eternal Nexus, a realm where countless worlds converge. Here, the laws of reality are dictated by Aether, a mystical energy that fuels both creation and destruction. Kael discovers he is a Nexus Warden, a rare being capable of manipulating Aether to bridge worlds and command the forces of the Nexus.But the Nexus is not a place of peace. It is a battleground for Eldari, ancient beings who seek to control the Nexus and use its power to dominate all existence. Kael must navigate this treacherous realm, forge alliances with warriors from other worlds, and unlock the secrets of his own latent powers. As he grows stronger, he uncovers a prophecy that foretells the rise of a Prime Warden, a hero who will either save the Nexus or doom it to eternal chaos.

This is the story of a young man who was reincarnated as a dragon with a near-insatiable curiosity. Initially sparked by questioning his own reincarnation, he quickly gets lost in the endless world of magic, using his deep understanding of advanced sciences to learn the laws and properties of a new type of energy known as mana.However, soon enough, the table would flip, and he would begin using that very same energy to expand his knowledge of science, to the point that he would begin questioning his own understanding of the world.Although not his original intention, with the combination of his intelligence, expanding curiosity, and the 'miracles' that occurred to allow for his existence, he quickly found himself climbing the mountain of strength as if it were a small hill before eventually climbing to a point where it seemed as if he himself was the peak itself.Even if.. that was never the case...There is mild gore, and profanity is 'censored' toward the beginning, but not later in the story.

A tree of 10,000 flowers, the world is the door.
The spells change a lot, but the hearts of the people are unchanged.

- Description from Uukanshu translation