MTL - Dawn of the Grey Tower - Chapter 224 Dead Banshee

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

A young middle school student faces a life-altering choice. Destined for mediocrity and without a War Spiritual Bloodline, he dreams of transcending his ordinary existence and becoming a high-status War Spiritualist. His world is transformed when he becomes bound to the “”Godly Pet Evolution System,”” enabling him to activate his War Spiritual Bloodline and cultivate divine pets, even from the most unlikely sources.Armed with this system, he defies expectations by nurturing underdog spirits into formidable allies. The seemingly weak flower spirit evolves under his care, as does his Lord White Dragon, challenging the mightiest thunder-attribute battle spirits. Even when presented with a Diamond Demonic Spirit Card, he counters with three Epic-Demon Spirit Cards of his own.His journey takes an unexpected turn as powerful entities, including the Six-Tailed Demon Fox, the Phoenix Holy Maiden, and the Queen of the Seas, vie to become his second battle spirit. Faced with a wealth of choices, he refuses to settle for just one and ambitiously aims to harness them all.

What if Midoriya Izuku stayed quirkless? What if he could become a hero without any powers? Or even more shocking—what if he became the successor to All For One?