The Retired Hero is an Extra - Chapter 128 - : Complex Relations

A surgeon accidentally got the blessings of a system, shocked the medical industry, and rejuvenated countless people.

- Description from Novelupdates

Due to an unexpected turn of events, Xia Fei consumed a Super Gene Optimization Fluid that bore no brand, expiry date, instructions or stated its place of origin.
Our story begins here…

Kael Veyne was betrayed, hunted, and left for dead in the depths of the Abyssal Dungeon.As an infamous assassin, he was the empire’s deadliest shadow—until the day his guild turned on him.Ambushed in the Abyssal Dungeon, his body was torn apart, and his soul was consumed by the abyss. But death was not the end.He reincarnates 25,000 years later with the Devouring Bloodline System. Kael awakens in the body of a noble scion sharing a similar name to him, and his very essence fused with eldritch power.With every kill, he absorbs primal energy, evolving into something far beyond human. Monsters, mages, mancers, knights, assassins—nothing is beyond his reach.

[The criteria for unlocking the system have been fulfilled.][System synchronization with host commencing.][Synchronization complete. Congratulations. You have been given a chance to become the most desirable human in this world, just as you wished.]“This isn’t what I wished for.”[What seems to be the problem?] the voice asked, a hint of curiosity in her tone.“I asked to be the most desirable human, not a woman!” he exclaimed, frustrated as he cupped his newfound breasts.Sylvester Lancaster, a dedicated and kind-hearted unactractive policeman, often dismissed and treated like a doormat, snaps after discovering his newlywed wife in bed with his best friend. Consumed by rage, he goes on a violent rampage, only to realize the horrific extent of his actions when the blood cools—he has committed murder. Panicked, he attempts to flee but is struck by a car and meets his untimely death.However, death is far from the end. Sylvester awakens in a morgue, only to find himself in a bizarre alternate universe—trapped in the body of a stunning young woman named Cara Bolton.In this new world where Sylvester has transmigrated to, vampires, werewolves, witches, and other supernatural beings coexist in a fragile balance with humans, their uneasy peace marked by underlying tensions and hidden conflicts. Among the supernaturals, vampires reign supreme as the most dominant and influential. The system reveals to Sylvester that he now wields two new skills: the power to read minds and the ability to detect lies, skills inherited from Cara, the body’s former inhabitant who was a fairy.The system assigns him quests to complete, allowing him to level up and gain all remaining skills a fairy possesses. Many of these missions involves sex, manipulating and exploiting people, as well as infiltrating the vampiric council.