Complete Monster/Sailor Moon


 * Wiseman/Death Phantom, the Big Bad and Eldritch Abomination of the R season of Sailor Moon, is definitely this. He corrupted and manipulated the rebellious Black Moon Clan of Nemesis into becoming villains and used them to turn the peaceful, utopian Earth of the future into a barren, desolate wasteland, had the dark crystal created so that he could do the same to the Earth of the past, Mind Raped a vulnerable little girl into becoming his servant and tried to have her kill her future parents and friends, turned one of his pawns into a monster and knowingly sent her to her death, sadistically blasted to death another minion in front of that minion's older brother for having outlived his usefulness and attempting to screw up his master plan, killed the older brother in a brutal attack meant for Sailor Moon, tried to strangle Sailor Moon shortly afterwards before attempting to break her spirit through lies and Mind Rape, and planned on destroying the universe for the sheer hell of it. Quite easily the vilest villain in the entire series.
 * And in the manga, Wiseman was a mass-murderer before being possessed/merging with Death Phantom. Oh, and guess who is shown being the one to start Galaxia on the path of being manipulated by Chaos in the final arc? Make no mistake, all (manga) or nearly all (anime) Big Bads in Sailor Moon are Omnicidal Eldritch Abominations, but Wiseman just puts a personal touch on the whole business of causing The End of the World as We Know It.
 * Before Wiseman, there was Queen Metaria, another Big Bad Eldritch Abomination who was the one who destroyed the Moon Kingdom in the first place. Her goal for existing? She's a nihilistic demon who hated all life and wanted to see it eradicated. When you're the source of so much evil and pain due to nothing but pure, irrational hatred for pretty much everything, you know you've crossed the line into Complete Monster territory.
 * Rubeus, high-class member of the Black Moon clan, was REAL bad as well in the anime. His treatment of his underlings is completely unforgivable (especially what he does to Cooan and Petz, by ). He's one who definitely Would Hurt a Child, attempting to manhandle or attack Chibi Usa during every encounter with her. Out of all the Black Moon clan, his interactions with the abovementioned Wiseman feel the most like two people talking on an equal level, rather than Wiseman being advising, manipulative, or antagonistic like he is with everyone else. And he's also very irritatingly smug and self-absorbed.
 * He was a piece of work in the manga as well, sending the Four Sisters on much more destructive evil missions than they went on in the anime and taking sadistic pleasure in capturing the Sailor Senshi in front of Usagi's eyes. Unlike in the anime, the Four Sisters probably also qualify for Complete Monster status in the manga, especially Cooan, who burns an innocent girl to death with no remorse.
 * The manga version of Shuichi Tomoe was no slouch. He was supposedly a loving father once (or at least Hotaru thinks so), despite being a Mad Scientist even then. He completely snapped after the accident in his lab that crippled Hotaru (her manga self is a heavily scarred cyborg, thanks to it) and killed her mother, willingly joining Death Busters and implanting the egg of Mistress 9 into Hotaru's body without any sort of second thought. He also had a massive A God Am I complex and wished to create a new race of superbeings, starting with himself so that he could be ruler of the new world. After his death, Hotaru even acknowledges how far gone he was, stating that her father truly died a long time ago. Thank God he was much more toned down in the anime, where he was mostly a Brainwashed and Crazy father who made a Deal with the Devil to save Hotaru after the freak accident - not knowing that they'd be rendered insane in different ways.
 * Chaos is evil incarnate and the manifestation- and cause - of all of sadness, cruelty, and evilness in the galaxy. It revealed in Stars that Chaos is responsible for all of the suffering in the galaxy and all of the Big Bads Sailor Moon has faced (Queen Metalia, Death Phantom, Pharaoh 90, and Queen Nehelenia) are all incarnations of Chaos. While Chaos itself might lack the moral agency needed to qualify for the trope, all of it's spawns in the manga definitely do since they live solely to spread misery throughout the galaxy.