LOTM: Sword of Kings/Nightmare Fuel

Due to the 18+ rating of the storyline, LOTM: Sword of Kings and its spinoffs, sequels and related stories are full of nightmarish sequence, including menacing villains and their horrifying crimes based on the realistic war crimes, like Facism crimes committed during World War II. Be expect to see dark monsters in this world of Black and Gray Morality

For the Nightmare Fuels more prone to LOTM: Witnesses of Sleepy Hollow and its related stories, please go to here.

Villains

 *  B1-Killer Kampfdroide Unit-CM 130  deserves a title image for a reason; being one of the (if not the) most horrible and menacing villains in CIS Productions ever. His backstory in Bismarck Arc shows him to be a droid developed by the already mad Akihiro Kurata, being one of the two only droid from Deus.Ex.Machina Industries Empire that has its own sentinence (the other being much more jovial Jack the Freezer). Its overall heartless experiments, based on the real-life Nazi doctor Josef Mengale's experiments, as well as the research of Japanese Unit-731, are developed under the name of science, but everywhere he goes, death follows this Mad Scientist around. Not only the experiments are utterly cruel and disgusting, its impacts even infected other victims directly or indirectly. In a nutshell, CM's brutality reaches no bounds. The entire Multi-Verse were haunted by his horrid name and his brutal experiments, and Bismarck Bodewig shall never forget whatever she witnessed in his concentration camp.
 * In Saga AA, this only became all the way worse as he was revived by The Fallen's Essence and became much more cold, heartless and cruel comparing to his psychotic former self, building the very foundation of Manufacturing Progressive Sciences upon the KnightWalker Alliance. CM's return not only caused impact over the story, with more and more fan-favorite characters falling under MPS' victims, but also drove the story into a darker tone. Even other villains are disgusted by CM and started to rebel against him.