The megalomaniacal Gigalomaniac.
The Science Adventure Series is notorious for being dark and some villains are extremely vile and horrific.
- Norose Genichi, the Big Bad of Chaos;Head, is a sneering, arrogant, sadistic bastard with a god complex who specializes in Mind Rape, especially of young girls. What he did to Sena's family (and most especially the amusement he felt about it) was so far over the Moral Event Horizon that it begs belief and that was one of the first things that the audience knew about him!
- Chaos;Head 's sequel Chaos;Child adds there two Serial Killers:
- Wataru Sakuma, Takuru Miyashiro's seemingly loving foster father, is a Mad Scientist who masterminds the Return of the New Generation Madness. In the past, he worked at a secret laboratory where he would carry out horrific experiments on Gigalomaniacs. Seeking to continue his experiments after the lab was shut down, Sakuma teams up with Serika Onoe, plastering Sumo Stickers around Shibuya to locate Gigalomaniacs and using his artificial Mind Control powers to force them to commit suicide in gruesome ways, often publicly. Sometime after he brainwashes Shinji Itou into serving as an accomplice, Sakuma targets his own adopted daughters, Yui and Nono, to be killed by Shinji and Serika, respectively. Finally, he has Takuru framed for the murders and forces him into a final fight, then traps him in a delusion where Takuru must witness Nono being killed repeatedly, before deciding to deprive Takuru of his senses altogether and let him go mad. Willing to harm even his own adopted children, Wataru Sakuma admits that his main motive for his evil is having fun.
- Shuichi Wakui is a teacher at Hekiho Academy and Sakuma's partner in crime. After helping Sakuma with the experiments on Gigalomaniacs in the past, he decides to aid Sakuma in carrying out his murders. In the Deep Sky route, when Takuru Miyashiro and Hana Kazuki discover his true nature, he deafens them with a tiny bomb, intending to drive them insane from the deafness. After Serika Onoe saves them, Wakui instead kidnaps Nono Kuruso (actually Senri Minamisawa) and holds her hostage in exchange for Takuru and Hana surrendering themselves to be killed. When the two fight back, he assaults Takuru with delusions of Hana biting her tongue off and Nono being repeatedly decapitated, before trying to kill them. In the Silent Sky route, he attacks Takuru and an amnesiac Serika when they infiltrate his hideout, then returns Serika's memories back just to torment her with the knowledge of her involvement in the murders. Finally, he agrees to allow Takuru to cure the Chaos Child Syndrome patients in exchange for Takuru turning himself in as the killer, allowing Wakui to go free.
- Steins;Gate 0 has these two Mad Scientists:
- Dr. Judy Reyes is an immoral agent who will do anything to unlock the secrets of the brain for her own use. As the main antagonist of two of the game's routes, Reyes was an agent of DURPA sent to infiltrate Stratfor to gather the data of their brain experiments and the memory data of Amadeus, even helping Stratfor's unethical experiments. In her mission, Reyes sent her men to raid and threaten numerous key figures, including burning down Kurisu's home and trying to kidnap Maho and Kagari at gunpoint. Whenever her men fail, they commit suicide out of fear of what Reyes and DURPA would do to them. In "Twin Automata", Reyes tried to kidnap Hiyajo Maho and the below-mentioned Leskinen to unlock Amadeus's memory data, and when Leskinen did so Reyes immediately executes him before threatening Maho for the access keys. In "The Promised Rinascimento", Reyes managed to kidnap Kagari and demanded Okabe to meet her, otherwise she'll kill her. During the meeting, Reyes reveals that she killed all the scientists working on the Amadeus and reveal her motivation was to unlock the secrets of memory implanting to create a series of deadly soldiers under DURPA's will before demanding Okabe to join her.
- Alexis Leskinen is a Mad Scientist who will callously damn the world to conduct his experiments to understand Time Travel. In the Alpha world line, Leskinen caused the deaths of billions in his avaricious need to beat the Russians in their advancement. When Okabe and his resistance group try to build a time machine of their own, Leskinen attacks them and tortures Okabe into a coma. Sending messages to his past self and brainwashing another time traveler into helping that version of him, Leskinen from the past moves towards stealing a time machine, uncaring that doing so may cause a paradox and destroy the universe. Though stopped, Leskinen of the past repeats the original history and starts World War III anew.