Douluo: God-level Gold Item, Start With Succubus Physique - Chapter 10 Continuous breakthroughs within three months, level 20 Great Soul Master!

Frank, a mercenary known for his cold ruthlessness, decides it’s time to leave the bloody world of the underworld behind. But the underworld has no plans of letting him go. Relentless enemies from his violent past keep hunting him, and eventually, they succeed—Frank is killed.But fate has other plans. Instead of staying dead, he is mysteriously reincarnated into the body of a cop in a world filled with crime, corruption, and dark secrets. With the help of a strange, all-knowing system, Frank is given the chance to live again—this time, to prevent crime before it happens.

Qin Zhaoyue, a hundred-year-old Soul cultivator and famous artifact refiner, dies and transmigrates into a body of 16-year-old Xi Zhaoyue, who was killed on her wedding day.

The unlucky previous owner of the body was an illegitimate daughter of an influential family and was forced to live her whole life in the orphanage. However, at the age of 16, her Guide glands were awakened and as fate willed it, Xi Zhaoyue happened to have the highest compatibility with the youngest, bravest, most handsome Major General of the Empire, a dream husband of the whole Outer Space! Finally, a loving family she so longed for was within her reach… Yet, at the wedding ceremony, her Mental sea was invaded and she died.

Once Zhaoyue figured out the situation she landed herself in, she vowed: she wouldn’t be a proud and self-respecting cultivator, if she didn’t strive for independence, for the right to live the life freely! Cultivate, refine, get stronger! Become your own person!

- Description from Novelupdates

This is a story of a man named Kim Sae-Jin, who one day, inexplicably wakes up as a Monster. Follow him and his perilous journey to get his life back as a Human, all the while growing even more versatile as a Monster in the process. This should be… complicated, somewhat.