Complete Monster/Xeno Series

''"Oh, I can talk alright. And I got a pretty good memory. 'Fiora! Get outta there! Get out!' Her screams were music to my ears, as my claws slid right through her soft flesh, like a hot knife through butter! GAHAHAHAHAHA!" '' -Metal Face/Mumkhar The Xeno franchise has more than a few of these exceptionally vile beings among its large cast of characters.

Xenogears

 * Miang Hawwa is eventually revealed to be the true driving force of the game's conflict. Initially Ramsus's wallflower assistant, Miang turns out to be an ancient being with one goal: to prepare humanity for harvest by Deus. The "Eve" of the world, its first woman, Miang has helped to manipulate human history by running an Ancient Conspiracy, causing countless wars and conflicts with countless deaths. Miang demonstrates nothing less than cruel satisfaction at her manipulations, rubbing it in her lover Ramsus's face how he was a failed prototype of Ramsus's rival Fei to break his already fragile mind. Miang awakens Deus and causes the genocide of almost all humanity, in addition to having made it her personal mission to destroy the happiness of lover Fei and Elly's past incarnations every time they reincarnate
 * Bishop Isaac Stone (originally Stein) is an agent of Solaris and one of the darkest and cruelest villains in a game full of soldiers fighting for honor and their beliefs. Having long ago murdered Raquel, the mother of Billy, all because she chose Jesiah over him, Stein continues the conspiracy of the Ethos by taking in orphans and lost people, only to send them to Solaris to be experimented for their secret weapon, and killing any survivors who became Wels or Reapers by sending out priests who he tricked into believing him. After the Ethos tries to break away from Solaris using weapons they found inside an ancient ruin, he begins to massacre them, leaving very few survivors. After being caught up by Billy, a young man who was devoted to Ethos, he gives him a Breaking Speech by telling him the monsters he killed were actually people that Solaris mutated.

Xenoblade

 * Zanza, the god of Bionis, is the mastermind behind the game's plot and a monstrous excuse of a deity whose insatiable pride ruins countless lives in an effort to prolong his own. Revealed in the sequel to be one half of the scientist Klaus who accidentally destroyed the universe in his experiments, Zanza recreated the universe as an endless mass of water where he and Meyneth were the only surviving beings, and they ascended to godhood by transforming into the souls of the enormous titans Bionis and Mechonis respectively. They both grew lonely and created life that lived on their bodies: Meyneth created the Machina and was kind and loving to them, while Zanza created the Homs, Nopon, and High Entia, all of which have no higher purpose than to serve as his food, and is more than willing to cause the apocalypse if he feels that they're getting too unruly and want to leave him, and has done so multiple times in a cycle of death and rebirth. When a noble, goodhearted giant named Arglas found his weapon the Monado, Zanza's soul possessed Arglas and used his body to get the Bionis to attack Mechonis' capital Agniratha, killing tons of Machina and turning the once heroic and noble Egil into a revenge-obsessed madman before fighting Meyneth to the death until their titans stopped moving. In the present day when he's resurrected by his disciple Dickson, he brutally murders Egil and Meyneth before completely annihilating the Mechonis and all life on it, then goes on to transform most of Alcamoth's High Entia into Telethia, his mindless servants that act as his death-bringers by wiping out all life on Bionis and collecting ether for him to use as energy, and is dead-set on murdering everyone living on his titan body before renewing the cycle. While Zanza reveals that he desired friendship, what he truly wants isn't friendship, but more of a one-sided abusive relationship where he rules over his creations with an iron fist unless if they worship him endlessly and act as his food. All in all, Zanza embodies the worst traits of a god, as he believes that he can do whatever he wishes due to his godhood and views all other life as lowly insects that he's free to use and abuse as he sees fit.
 * The particularly cruel Faced Mechon known as Metal Face is just plain disgusting. . When he's seen in the present, Metal Face leads an assault on Shulk's hometown of Colony 9 with a horde of lesser Mechon and slaughters tons of innocents, including Shulk's friend (and Dunban's sister) Fiora. If that wasn't bad enough, Metal Face never shuts up about it and clearly enjoys pissing off Shulk every time he brings it up, and even goes as far as to say that it felt great to sink his claws into her, and that her screams were music to his ears before laughing at Shulk's resulting anger. Later on in the game, he . And once he . Even when Shulk and Dunban spare him, he tries to kill them not even a second later and only succeeds in killing himself on accident. Naturally, once he dies no tears are shed whatsoever and his death is quickly glossed over by the main cast. Basically, Metal Face/ is the Pigma Dengar of the game, only much worse.
 * In a similar vein to Metal Face is his fellow Faced Mechon Xord, the game's Starter Villain who serves as the antagonist of the Colony 6/Ether Mine arc of the story. A sadistic and gluttonous brute of a Mechon, Xord led an attack on Colony 6 and succeeded in completely annihilating it, leaving it a smoldering crater with the only refugees being a small group of non-combatants as well as the medic/sniper Sharla and her kid brother Juju. When Shulk and Reyn attempt to save Juju from one of Xord's flunkies, Xord takes Juju and flees to the Ether Mines where he is keeping him along with a bunch of hostages that he took. Once they arrive to where Xord lies in wait, there are a ton of bloodstains yet no survivors, and after laughing his ass off Xord reveals that he ate every last hostage he took and shows a sickening sense of giddiness at the prospect of gobbling down Juju for dessert. While unlike Metal Face.
 * Dickson starts the game off as a seemingly helpful mentor and father figure to our protagonists, particularly Shulk and Dunban. This all changes after Shulk refuses to kill Egil after defeating him. Dickson shows up and shoots Shulk In the Back, releasing his master Zanza. He then reveals that he's Zanza's disciple, and never cared at all for the people of Bionis, acting only to ensure Zanza was properly revived—then assisting in his wishes to kill off everyone so he can enact the destruction/reconstruction of the world. He tries to finish off the party with an army of Telethia, gleefully asserting that he's Not Brainwashed when they propose he is. When the High Entia army shows up to save the heroes, he and fellow disciple Lorithia convert them all into mindless Telethia, including Melia's brother, Kallian, whose remarks to his sister whilst transforming they promptly mock. Shortly after this, he arrives in Colony 6, now the residence of the surviving people of Bionis, with more Telethia, hoping to exterminate them all. He further taunts Melia, mocking her brother by proposing he might be her boyfriend in the next life. Ultimately, he reveals his motivation for his actions is that he wants to have the powers of a god in the next world. Thus, he willingly helps Zanza's atrocities with a sadistic smile on his face, no regrets or remorse, only feeling fear when it's hinted Shulk might be stronger than Zanza.
 * Dickson's fellow trinity member, Lorithia, manages to be just as nasty as her partner thanks to being in on Zanza's plan to kill everyone on Bionis and is willing to sell out her own people in exchange for immortality. When she reveals her status as a member of the Trinity, she unleashes a ton of ether that forcibly transforms her High Entia allies into Telethia in an agonizingly painful process against their will, one of them being Melia's brother Prince Kallian. Not missing out on this detail, she later encounters the party inside the Bionis and assimilates herself into the Kallian Telethia and forces him to fight Melia in a battle to the death as her sick idea of a gift to her.

Xenoblade Chronicles X

 * Grandmaster Luxaar is the lord and master of the Ganglion Coalition, a galaxy-wide crime syndicate and tyrannical empire that Luxaar rules with cruel fanaticism. In his quest for "purity" across the cosmos, Luxaar regularly commits genocide against entire races, enslaving those he does not exterminate and often forcing innocents to follow his rule lest he subject their worlds to similar fates. Upon learning of humanity and its connection to the Ganglion's former masters, Luxaar deems humankind a plague deserving of total human annihilation, and proceeds to lead an assault on Earth that wipe out billions of humans, after which he pursues the survivors across the universe. Luxaar's insane xenophobia comes to end after he massacres his way through dozens of human soldiers and attempts to murder the twenty million sleeping vestiges of humanity.
 * Alex is a BLADE who blames the destruction of the Earth on any xeno, regardless of how they're affiliated. Tricking Rook into gathering a number of xenos and attending a seminar that will take place in the wilderness, Alex uses this excuse to attempt murder on the xenos attending as the start of his Final Solution. If the murders aren't stopped by the player, Alex clearly relishes in their deaths—much like how Goetia relishes in the thought of purging mankind. An opposing group led by Eliza condemns the actions of Alex and his terrorist friends, but wishes to negotiate with them peacefully to set them straight. This fails, and Alex attacks the player in the negotiation process. When Eliza wishes to make an assembly to advocate human-xeno cooperation, she gets non-fatally sniped, by Alex's orders. Later, the player finally confronts Alex at Cauldros, where he's seen conspiring with Ganglion forces—the same Ganglion forces who actually DID destroy the Earth—to bring about his genocidal ambitions.

Xenoblade Chronicles 2

 * Dr. Castrofari is an insufferably smug, giggling psychopath who has children all over Alrest drugged and kidnapped as fodder for his twisted experiments, which aim to forcefully augment his specimens into artificial Blades. When Perun confronts him on his deeds, Castrofari offers to let the children go if Perun surrenders herself as his next subject—only to laugh and confess he'll murder all of the children anyways, giddily announcing his intention to experiment on Perun until she’s nothing but a withered husk.

Xenosaga

 * The Xenosaga series gives us Dr. Dmitri Yuriev. A man who created an entire army of clones of his own child and then