A Gunslinger's System in a World of Magic - Chapter 1: Death and Punishment

A dancer who was killed by a serial murderer found himself occupying the body and taking on the life of Brian Morse, a patient with anti-social personality disorder. As Brian, he has the look, he has the brain, he has the charisma, but he also has something that somehow always attracts psychopaths…[The story mentions 3 reality shows and crossovers with the American drama series Dexter. SLASH]

- Description from Novelupdates

Because her appearance was not breathtaking, the Emperor breaks off their engagement and bestows her instead to the bloodthirsty, ruthless, and cold-blooded Second Prince (Wang Ye).

On her wedding night comes endless humiliation, the genuine Princess Consort becoming a deserted women. A foolish woman before rebirth, she no longer expects his love. In this world, she must possess enough talent to awe those around her, carrying herself with composure and articulating with beautiful diction, override above the nine night.

- Description from Novelupdates

My reunion with her took place in the worst possible way.

The Jiuzhou Continent contains an era of chaos and fiendish demons, haunted by mysterious beings and fraught with feuding martial families, demonic sacred grounds, and endless struggles between various powers. Conflict is a constant throughout the world.Within such darkness, Gu Chen opened his eyes to this reality.At the same time, he discovered that as long as he slew these fiendish demons and ghosts, his cultivation strength could continually elevate.Killing a Panic Level Demon yields a decade's worth of cultivation.Slaying a Ghost Level Fiendish Ghost brings thirty years of cultivation....Eventually, one day, staring at the endless swarm of fiendish demons and world-renowned grandmasters in his path, Gu Chen chuckled lightly, “Are you able to withstand this fist of mine, charged with 1600 years of cultivation?”