Double Kill

Kasai was only a boy when he watched his parents die, not from blades or bullets, but as their very souls were ripped away. No one believed him. No one but Naraka, a ruthless mafia syndicate that raised him into their perfect weapon. Now, years later, Kasai has escaped the underworld, desperate to bury his bloodstained past. But when Naraka comes hunting, fate delivers him into the hands of a mysterious group of assassins that are after Naraka, known as Soul Hunters. But their killings don’t end with the body; they annihilate the soul itself, preventing their targets from reincarnation. For Kasai, they may also hold the truth about the night his parents were killed. To uncover what really happened, and finally break free from Naraka, Kasai must hunt the very Mafia family that forged the monster he has become.

Source: Webtoon