Fight for your Death.
When regular high schooler Grady Hake is mistakenly taken by the Angel of Death, he thinks his life is over. Then he wakes up on a prison shuttle bound for Van Diemann's Planet, a penal colony run by brutal gangs of criminal cultivators. This is his life now, and if he wants to survive it, he'll have to learn to harness his unique Death Spirit, make friends with alien outcasts, appease a band of ancient hungry ghosts, and fight his way into one of the strongest gangs on the planet.
Death Cultivator is sci-fi / isekai / wuxia / western / whatever, sort of like Borderlands meets Hunter x Hunter. I wanted to write something entertaining and actiony with that shonen vibe, so here's hoping this hits the spot.
Warning: This isn't an isekai where the MC immediately becomes OP and starts revenge-killing everyone once he gets Death powers. Death is coming, but it's a slow burn, and it takes him time to learn and adjust to this new world. If you're looking for an awesome and hilarious story with a dark antihero MC who loves killing and loves revenge, you should check out NH Paxton's Grimm Darkfyre. It rocks.