MTL - Poison Genius Consort - Chapter 1 Horrified, marry someone

Transmigrated-into-another-world-three-good-citizen Gu Xizhou, in order to survive, became a demonic cultivator. No matter how bad or evil, he adapted.

But then…but then he transmigrated back.

The returned Gu Xizhou was very angry. The student that offered his body in order to resurrect him had used a formation that was purposed for summoning evil spirits. He, Gu Xizhou, prior to transmigration was a law-abiding citizen that upheld core socialist values, a three good citizen representative. So how come after transmigrating and coming back, he had become a heinous malicious spirit?!

In each and every one of the spirit worlds, the ghosts and spirits originally lived a Heaven is first and I am second kind of happy lifestyle, that is until in the unlimited spirit mission worlds, inexplicably and out of nowhere came a demonic cultivator.

The ghost and spirits: QAQ

- Description from Novelupdates

Elijah is dying.Afflicted with terminal cancer, his days are limited. So, after deciding to spend his remaining time with family, he boards a plane and sets off for the Pacific Northwest to be with his sister. However, along the way, Earth is transformed by the touch of the World Tree, injecting it with magical Ethera and connecting it to a much larger universe via the System. More importantly for Elijah, though, it also causes his plane to crash, stranding him on a deserted island. But all is not lost, and through the System, he gains the Druid archetype that may be enough to allow him to survive a hostile environment filled with powerful monsters as well as more mundane threats like starvation and the elements. Meanwhile, his sister, Alyssa, must survive the collapse of civilization as she knows it while trying to keep her family safe. Follow them as they try to navigate an apocalyptic world full of game-like stats, classes, and threats aplenty. Current Release Schedule is one chapter a day (7 days a week) at 11AM CST. Patreon is currently 70 chapters ahead, with an extra chapter (for 8) each week.

What got summoned was the world’s strongest sociopath.