Rakuin no Monshou - Volume 5, Chapter 4: The Battle at the Coldrin Hills

If 'Jujutsu Kaisen' and 'John Wick' f**ked, then had a baby, this would probably be it:Detached mass Murder experimenting on deaths?Yandere himouto who'd threaten her father and do background murders for her brother?A Divine Wolf who jokes about blending people and cannibalism?This is the package.___________________“The first time I felt the particles, I thought I was going insane.”Naturally, as the heir to a fading Yakuza empire, Ken Kurosawa knew violence. But nothing prepared him for the day he awoke to a world only he could see. Strange, shimmering particles floated in the air, whispering secrets of the unseen. When he reached out… the world bent to his will.At first, he used this power—Kami-Jutsu, he found it to be—to protect his family. A masked figure in a shadow-cloaked hood, he slaughtered his father’s rivals in the dead of night, their blood staining Tokyo’s underbelly. But with each kill, the particles grew louder.Now, as ancient factions hunt him and a prophecy unfolds, Ken must master his godlike abilities before something apocalyptic emerge from the depths of the underworld.The Yakuza’s son will learn: some truths are deadlier than bullets.

Crossing to One Piece world, he became Roger’s younger brother.

Unexpectedly, Gol-D-Roger who was in his fifties had a teenage brother. But he was so weak.

Fortunately, at the age of sixteen, he actually found himself with a possession soul system.

He had attached to the master IP man, also to the White Phoenix and to Ge Nie with his strong ability of the Hundred Step Flying Sword.

If you think that he can only Purchase these? Then you’re wrong!

Pain, Itachi, Ichigo Kurosaki, as long as there is money, any soul can be Purchased.

- Description from Novelupdates

In the world of Kyushu, players full of resentment gathered together, dripped blood as an alliance, and vowed to make the big devil go away.

For a time, all directions responded, the wind was surging, and everyone saw a better tomorrow.

Except for Lubei.

He is the so-called devil.

“Say I’m the devil, blame me for pitting you, I’m an NPC, how could I pit you, that’s how immortals are!”

- Description from novelbuddy