MTL - Avoid the Protagonist! - Chapter 43

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

Fifty years ago, Dragon City transmigrated to the Other World. Alone in the world, they lifted the banner of Earth’s civilization and fought against the terrifying forces of the Other World.

The king of assassins was reborn, mastering both alchemy and poison. Sitting inside the space, there was a ghost that loved crying.

Lucien, a guy who has nothing but the desire to save his mother. To get strong enough, he makes a contract with the demon of L.u.s.t. And now, only by making a great harem, will he gain the power to protect those dear to him.