Mihai Mihaeroff, a retired assassin marked by scars, long gray hair, brown eyes, and glasses, reenters the city to settle an old vendetta. He once worked for a gang boss, mentoring the boss's son, Ian, and was romantically involved with Milena Teslawska, a prostitute. Their relationship ended tragically when Ian, then a teenager, murdered both Milena and his own father. Mihai confronted Ian at Milena's grave, where an assassin targeted Ian. Both were wounded; Ian died after confessing he killed Milena out of fear of losing Mihai, whom he viewed as a father figure. Mihai, in turn, confessed his fear of losing Ian. Reflecting afterward, Mihai stated it was not his time to die, addressing both Milena and Ian.

Despite his age, Mihai retains a muscular build and formidable combat skills, proficient with firearms and improvised weapons. Known for his calm demeanor under pressure, he also suffers a chronic lack of direction and frequent misfortune. He shares a longstanding friendship with Kiri, owner of the Buon Viaggio restaurant and a former prostitute, who often sends him on ingredient runs. Employees imply a romantic link between Mihai and Kiri.

Within his group of companions, Mihai acts as the most level-headed and experienced member. He forms an amiable bond with Badou Nails, who calls him "gramps" or "old man," and shows concern for Heine Rammsteiner and Naoto Fuyumine. His connection to the underground organization is less direct than the others, though he shares an unexplained history with Richter Berthein. During missions, like defending against mutated soldiers on a train, Mihai demonstrates his undiminished combat readiness.

Having resolved his vendetta, Mihai transitions to a new life, planning to open a restaurant. He continues collaborating with his companions in their search for answers related to the underground, leveraging his skills in their conflicts.