Monster / Fire Emblem
"Let me relieve you of your head! Bwahaha!"

"That Queen wicked to the core. She began abducting kids after allying with this dark bishop [Manfroy]. She kills the mothers, too, without a blink of an eye! That woman's not even human. I'd say she's more like a devil!"
— A Miletos villager, Genealogy of the Holy War

Fire Emblem has many characters, and the villains come in many varieties, but only a few are Complete Monsters.note 
Unmarked spoiler warning.

The Archanea Games

Mystery of the Emblem
  • Lang, Marquess of Adria, betrayed his nation to the Dragon Empire of Dolhr so he could rob from his own people. When Dolhr started losing, Lang defected back to Archanea. Taking advantage of the now Emperor Hardin's Despair Event Horizon, Lang gets himself appointed as Overseer of Grust, a defeated nation that in the previous war allied with Dolhr. The sadistic Lang commits various atrocities on Grust, including killing men that could oppose him, capturing young girls to rape and pimp; ordering the massacre of family members of those who participated in the rebellion; and executing the preteen heirs of Grust. When confronted over his actions, Lang tries to put the blame for his action on the Emperor so he could trick his foes into letting their guard down. Selfish, loyal to no one and willing to do anything to satisfy his own greed and sadism, Lang is among the worst Archanea has to offer.

Fire Emblem Gaiden note 

The Jugdral Games

Genealogy of the Holy War
  • Bishop Manfroy is a Dark Priest and leader of the Loptyrian cult. Manfroy was determined to obtain revenge on the entire continent of Grannevale for forcing him to live in the desert, and thus spends years patiently paving the way for the return of the evil dragon Loptyr. Using assassination and manipulation, Manfroy creates a massive war, which initiates the chaos necessary for his plans. To create Loptyr's vessel, Manfroy kidnaps Deirdre, the wife of Sigurd, cruelly and gleefully erases all her memories of her beloved husband and son, and places her for his pawn Arvis to find, fall in love with and marry, despite the fact that she is his unknown half-sister. With his goal achieved, Manfroy awakens Loptyr in Deirdre's son Julius and sets about constructing a nightmarish dictatorship where children are sacrificed and any who resist are massacred. In the end, Manfroy, with nothing less than sadistic relish, exerts mind control over Julius's twin sister Julia to make her kill her beloved friends. In his cameo in the Interquel, Thracia 776, it is revealed that Manfroy murdered his own son-in-law, and drives his own daughter into madness. If Manfroy's granddaughter, Sara, is not recruited, Manfroy will zombify his own granddaughter into one of the Deadlords to do his bidding. Manfroy manipulated everyone around him, was cruel even to his own family, and enacted a endless regime of nightmarish suffering on the entire continent. It is clear that Manfroy has abandoned all potential good qualities solely to facilitate his own greed and personal desire for revenge.
  • Queen Hilda of Freege, for no other reason than For the Evulz, wholeheartedly supports, and participates in, the movement of sacrificing kids to Loptyr. Later on, it is revealed that she is responsible for the abuse of Taltio/Tiltyu (fatally) and her daughter Teeny/Tinny (a 2nd generation character). Hilda takes extreme pride in her actions, gloating about it in front of her children. If Tiltyu dies childless, her and Blume's little sister Ethnia will replace her as Hilda's punching bags, alongside her children, Amid and Linda (replacements for Arthur and Tinny). And although her daughter, Ishtar, was not physically abused, she was still manipulated by her mom because of her love for Yurius, which Hilda saw as a chance to gain even more power than she already had.

Fire Emblem: The Sacred Stones

  • The Demon King Fomortiis, especially on Eirika's route, shows himself to be a particularly depraved and sadistic monster. After possessing the Prince of the Grado Empire, Lyon, Fomortiis resurrects Lyon's father into a soulless puppet and uses him to initiate a series of brutal invasions to destroy the Sacred Stones of the other countries that have sealed the rest of him away. With a huge war and massive amounts of death, Fomortiis eventually reveals himself while also reviving monsters and undead creatures to run rampant throughout the land and kill those in their path. In Eirika's route, where Fomortiis possesses the prince completely, Fomortiis explicitly leaves a part of his mind intact to torment him as Fomortiis destroys everything around him, and also kills the heroic dragon king Morva before reviving him as an undead abomination while seeking to corrupt and dominate the world itself.

The Tellius Games

Path of Radiance
  • "Mad King" Ashnard, the pinnacle of a Social Darwinist, became the King of Daein by getting his father to sign a blood pact, and then invoking it, killing everyone who was in his way to the throne, as well as countless other innocent people. He then proceeded to kill his own father, therefore becoming king. After finding out about the dark god (really the goddess of chaos, Yune) sealed in Lehran's Medallion, he decides to release it. This requires a war that spans the whole continent, so he decides to begin by invading the next country over. He also, after finding out that his own son Soren was unable to transform into a dragon like the child's mother Almedha used to be able to, decides to hold him captive to get ahold of the kid's uncle, the oldest son of the king of Goldoa. He then proceeds to warp Rajaion's body and turn him into something resembling a wyvern, and then uses him as a mount. He laughs at everything. His ideal world, the one that he wishes to create, is one where the only thing that matters is power.
Radiant Dawn
  • Izuka, Ashnard's demented chief scholar and a a Beorc Mad Scientist, is no less evil than his master. In his brief cameo in Path of Radiance, he appears onscreen just long enough for it to be revealed that he is the developer of the Feral Ones, Laguz who are forcibly mode-locked into their beast forms and driven insane to be used as Cannon Fodder. In his base at Gritnea Tower it is revealed he has a basement devoted to storing the corpses of his experiments' victims. Izuka takes on a much greater role in the second game, where he has been hired by Lekain to bend Daein to Begnion's whims. He takes on the role of strategist to Daein's weak-willed Prince Pelleas, where it is demonstrated that he would gladly sacrifice good strategy for pointless destruction. He injects the innocent Muarim with the Feral One drug, which would have annihilated his mind if not for Rafiel's intervention. When Begnion offers to make peace with Daein, Izuka springs his trap, telling Pelleas to sign a "peace treaty" that is actually a Blood Pact, mystically binding Pelleas and thus all of Daein into virtual slavery to Begnion. Finally, it is revealed that he's tested his drug on the Beorc, his own race, too, including turning Elincia's noble Uncle Renning into the Tragic Monster known as General Bertram.
  • Vice-Minister Lekain, Duke of Gaddos, is a high-ranking politician of the Theocracy of Begnion and senior-most member of the country's corrupt senate who is driven by his insatiable desire for more power and hatred for the Laguz. When Begnion's Empress Misaha emancipated the country's Laguz slaves and planned to reveal that the royal lineage of Begnion was Branded, Lekain had her poisoned, then, pinning the crime on the peaceful Heron Laguz, whipped his countrymen into a genocidal frenzy, reducing the Herons' population from thousands to four in a single night. He then conspired for Misaha's young granddaughter Sanaki and a young senator by the name of Sephiran to be elevated to the positions of Empress and Prime Minister respectively, the only positions higher than his own, while he held the real power from the shadows. After Daein lost the war to Crimea, Lekain had the defeated nation annexed by Begnion, and gave Duke Numida and General Jarod free reign to do what they pleased with it. When Daein declared independence, Lekain tricked its new king, Pelleas, into making a Blood Pact with him, a mystical document that conscripts one nation in service to another under penalty of its citizens dropping dead one by one. Using this magic Lekain enslaves Pelleas and the Daein army to act as his accomplices in a war which Lekain plans to use to wipe the Laguz species off the face of the Earth.

Fire Emblem Awakening

Fire Emblem Fates

  • Iago, the right-hand tactician of King Garon of Nohr, excels at sorcery and illusions. In Birthright, he tries to instigate a feud between Corrin and the Wind Tribe by disguising some of the tribalists as Faceless to be killed. Later, he cruelly attacks Flora despite being in the wrong, tries to have Corrin and their group digested alive by a resurrected Fort Dragonfall, and is implied to be behind Takumi's aggressive state. In Conquest, fueled by nothing more than contempt for Corrin, he constantly tries to get the heroes slain, including a Faceless ambush in the Woods of the Forlorn and telling the warring Hoshidans where they'll be. In one notable instance, a Faceless tries to attack Corrin, but this results in Lilith's demise instead; Iago remarks he never liked her anyway. Finally, his dislike reaches the point where he outright attacks Corrin at the end of the route in front of the Nohrian siblings, going against his own king's initial orders. Manipulative and cruel, nobody approved of Iago's actions, and even the peace-loving Corrin wanted him dead.
  • Hans is a Nohrian criminal previously arrested for murder who, after his release from prison, served as a soldier for the Nohrian army. When ordered by King Garon to test Corrin's abilities, on what was meant to be a simple recon mission, Hans murdered a Hoshidan to initiate a conflict. Despite initiating the conflict as ordered, Hans continued to try and kill more Hoshidans for fun, abandoned the group during the conflict, and later on attacked Corrin on a bridge, needlessly trying to kill Gunter in the process. In the Birthright route, Hans gets promoted to a commander, and demands that his men fight against each other for real saying that he wants to see real blood. When he finds Corrin and the group, he orders his men to throw their lives away if it means weakening Corrin, and threatens to have King Garon kill the families of those who hesitate. In the Conquest route, when ordered to suppress a rebellion occurring in Cheve, Hans ignores the rebellion and decides to slaughter innocent villagers who took not part in it. He later gleefully kills Hoshidan prisoners who were promised to be spared if they surrendered. Hans is willing to do anything if it means he'll get ahead in life and while he claims to kill out of loyalty for King Garon, Hans only follows Garon's orders if it means he can be rewarded for what he loves doing.