“Yes. I, too, regretted what I had done. If my killing of Lady Mother became public, my, that is the future king of Reeve’s, reputation would be tarnished. Just when I was thinking of what I had to do, that woman appeared. She was a female mercenary, hired to guard the royal palace who happened to pass by at the time and since she had seen the murder scene I had to put the blame of the governor’s wife's murder on her, that’s all. I wanted to kill her then and there, but she managed to flee...”
—Rentzen, in a conversation with Dolmu
Rentzen is an antagonist from TearRing Saga: Utna Heroes Saga. He is the son of Duke Dolmu of Zemseria and the self-proclaimed rival of Runan. He is also a member of the royal family of Reeve through his mother.
When the Zoa Empire invaded Reeve, Rentzen, driven by his hatred of Runan, encouraged his father to betray Reeve and seize control of Razelia as a vassal of the empire. Following this, he was placed as an overseer of Razelia under his father's command and began ruling Razelia as an amoral tyrant. After his mother accused him of being inhuman for his cruelty towards the people of Razelia, he murdered her and pinned the blame on Julia, who had witnessed the crime. To cover up the murder and secure his position as the heir to the throne of Reeve, Rentzen hired Vega to hunt her.
When Runan's army approaches Zemseria, Rentzen appears before Dolmu and discusses the murder of his mother and framing of Julia. After Prince Julius withdraws Canaan's forces from Zemseria, Rentzen leaves as well, advising Dolmu to raise the drawbridges in order to exploit Zemseria's natural defenses at the expense of his frontline troops.
In Map 26B, Rentzen apprehends Arkis as he attempts to flee with his fiancée Rina and forces Arkis to fight for him by taking Rina as a hostage. In order to provoke Runan's forces into killing Arkis, Rentzen dresses him as a Dark Soldier, hiding his face with the helmet. As Runan's army approaches Razelia, Rentzen hires Golgoda as a bodyguard and arms himself with the ☆Rukuud. He also hires a group of brigands to disguise themselves as captive maidens in order to ambush Runan's forces.
If Rentzen is challenged by Julia or Vega, they will take vengeance for his deception and claim the ☆Rukuud after his death.