Shikkaku Mon no Saikyou Kenja~ Sekai Saikyou no Kenja ga Sarani Tsuyoku Naru Tameni Tenseishimashita~ - Chapter 18 Strongest Sage, Asked for a Magic Sword

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

Read the first chapter. You will probably like it. ;)

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.

William knew he shouldn't have taken that boat, but ambition can kick you in the teeth.Relma Artorious knew she should not listen at doors. But she is a girl with big ambitions and no intention of being less than her potential.Abdul Sahshir knew he should not undertake that assassination on Tuor's mountain. Yet, with his life ending before it has begun, he has nothing to lose and everything to gain by glory.Three stories intertwine and shape the destiny of many more. But not all heroes are on the same side, and the shifting of dreams and destiny is a fickle one...The compiled documentation of all my published stories on Royalroad. Read if you want to go all the way through to the end.