My starting summon is a small skeleton - Chapter 344 - 341 District 11

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 story about a weak, small larva with a human soul, who travels all the way to become the ruler of the stars.

My crew? Yeah... it's a little special.First Division: Night Raid from the Akame Ga Kill.Second Division: The Akatsuki, led by Pain, from the Naruto world.Third Division: The Seven Deadly Sins.Naval Headquarters:“Everyone, be on high alert. That man... he's coming.”Four Emperors:“Sh*t, who the hell provoked him this time?!”“Someone get ready to apologize. I’ll go in person if I have to...”The Dragon Hunting Pirates — a name that makes the entire world tremble!

In the endless Universe is eight primordial laws. Each of the eight laws have been fused with a supreme expert, but unbeknownst to everyone, there is a ninth law in the universe. It tears open the Primordial Chaos and is beyond reach.