Guildias

ギルディアス

Guildias is a police detective who arrests Guys and charges him with murder. He regularly visits Guys in prison, where he tortures and rapes him.
As the game progresses, Guildias is gradually revealed to suffer from various delusions. He is also an outright pedophile who framed Guys for murder out of an unfounded fear that Guys had witnessed him with a boy in town named Myuca.
Guildias locked Myuca in a room and forced him to dress as a girl to deflect potential suspicion when they were out in public. Initially, Guildias's motive for kidnapping the boy is never directly stated, but through his various delirious states, it becomes clear that Guildias was deeply in love with Myuca and had a sexual relationship with him. Due to his tendency toward delirium, Guildias suspected that Guys either witnessed him with Myuca or had concrete plans to free the boy from imprisonment. In a fit of rage, Guildias accidentally strangled Myuca to death. Later, he also murdered a man named Jared, a private investigator hired by Myuca's family who was already suspicious of Guildias regarding the kidnapping. To clear his own name, Guildias framed Guys for Jared's murder.
Guildias visits Guys multiple times in prison, primarily to abuse him and seemingly to distract himself from the pain and regret of murdering Myuca. During these visits, Guys begins to observe Guildias's unstable personality, particularly concerning the possibility of Guys being released from prison. To prevent this, Guildias threatens Guys's friends, who were supposed to provide witness statements to exonerate the boy during his first retrial. Later, upon realizing that Lusca might possess even more evidence to prove Guys's innocence, Guildias attempts to murder Lusca by shooting him. He also eventually visits Guys one last time to torture and humiliate the boy, aiming to force him to abandon hopes for another retrial.
Despite his efforts, when Guys is granted a second retrial, Guildias loses his sanity in the courtroom and is escorted out by guards. His fate is debatable, as it is never stated in the game, but in the OVA, he commits suicide. In the bad endings where Guys does not survive to prove his innocence, Guildias is never mentioned, so he may or may not have eventually lost his sanity in those scenarios.