In most games, players need something to fight, so developers craft scientists to create that something. It's an easy plot device that works in most games. A sneering villain in a lab coat engineers hordes of monsters, calling for the hero to stop said monsters from destroying the world. That's not to say audiences should write off these geniuses entirely.
Gaming has birthed several sinister scientists through the years. The best ones are equal parts entertaining and evil. Their malevolence lies in their lack of ethics, the level of chaos they cause, and the pleasure they take. It's healthy to love what you do, but these brainiacs take that a bit too far.
7 Baron Praxis - Jak 2
One has to admire a guy who can multitask. Baron Praxis not only rules over Haven City with an iron fist but personally conducts all sorts of experiments involving Eco, the mystical lifeblood of the planet. He typically uses inmates of his vast prison as test subjects. Among them is Jak, whom he torturously infuses with deadly Dark Eco for two years. Praxis aims to create the ultimate warrior to combat the invading Metal Heads.
If this project fails, the baron has a backup, albeit a crazier one. He obtains the fabled Precursor Stone and builds a bomb to crack it open. This will wipe out every living thing on the planet. Clearly, the cybernetic dictator doesn't care who dies as long as his enemies are defeated. He's willing to go up in smoke and take the Metal Heads with him. Sadly, many power-hungry despots would likely do the same.
6 Doctor Robotnik/Eggman - The Sonic The Hedgehog Series
Don't let his silly appearance fool you. Eggman is the ever-present nemesis of Sonic the Hedgehog, building the robots that the speedy blue blur fights throughout the series. That sounds standard, but these bots have sinister roots: cute, little animals. That's right. The demented doctor uses various forest critters to power his mechanical monstrosities. That's the mark of someone with no respect for the natural world.
He further proves that with his escalating schemes. Later Sonic titles show him ripping apart the very fabric of the planet. Granted some of this is by accident. Eggman wants to conquer the world, not destroy it. That said, he's not too bothered by the destruction he sows.
5 Neo Cortex - The Crash Bandicoot Series
The creator of Crash Bandicoot is similar to Eggman in his use of animals. He splices them together into all sorts of mutant hybrids, but his methods have less rhyme or reason than Eggman's ever did. Mix a dingo with a crocodile? Sure.
This arguably makes him worse. Much of the time, Cortex tries whatever schemes spring to mind. These range from simple experimentation to toying with time itself. He's suffered defeat so many times that he'll do anything to come out on top. Essentially, he has the scientific know-how without the wisdom to use it. That's a combination more twisted than any of his mutant monsters.
4 Professor Hojo - Final Fantasy 7
The chief scientist at the shady Shinra company, Hojo constructs many of the mechanical and biological menaces the heroes face in Final Fantasy 7. He's largely to thank for SOLDIER, the branch of genetically-altered warriors that the corporation uses as its elite fighting force. In truth, though, his ambitions go much further.
Hojo dreams of creating the perfect life form. When looking at others, he sees only what he can exploit. He first exhibits this with Aerith. She's one of the godlike Cetra beings, so he plans to force her to breed with his other test subjects. Not even his own flesh and blood is safe from such perverse goals.
Years prior, he infused his unborn child with the cells of Jenova, an extraterrestrial being also believed to be a Cetra. This birthed Sephiroth, the ultimate SOLDIER operative and Hojo's pride and joy. When the genetic freakshow threatens the planet, his crazy dad only seeks to aid him, wanting to see this experiment to its conclusion. Anything to satisfy his sick curiosity, Hojo will gladly do.
3 Albert Wesker - The Resident Evil Series
Zombies are a common problem in modern media, but Wesker sees them as the solution. He served as a scientist at various branches of the Umbrella Corporation, putting his biological expertise toward the human immune system. This created a few bioweapons, of course, but even the seemingly beneficial projects are insane.
Wesker seeks to turn people into zombies to prevent infection. Not only is this utterly nonsensical, but it makes him responsible for most of the unfortunate events in the Resident Evil series. These are just further tests for a man incapable of empathy or loyalty. He proves this again when he betrays Umbrella and takes his research to various black-market organizations. It doesn't matter how deplorable their goals are as long as he gets to finish his work: usher in the next step in human evolution. There's nothing like a good, old God complex to complete an evil scientist.
2 Xehanort - The Kingdom Hearts Series
The main villain of Kingdom Hearts was already pushing boundaries as a Keyblade Master, attempting to ignite a cataclysmic war to remake the universe. After transferring his essence to a younger body, he apprentices under Ansem the Wise, where he studies light, darkness, and the nature of the heart. He eventually forces Ansem out, steals his research, and goes more radical. These efforts unleash hordes of dark creatures on the worlds.
Xehanort believes himself the supreme arbiter of what's just and what's not. He's perfectly willing to condemn countless people to oblivion. All that matters is unlocking ultimate power, allowing him to put his universal designs into practice. Few things are more dangerous than a scientist with delusions of grandeur.
1 Android 21 - Dragon Ball FighterZ
The Dragon Ball series has seen plenty of evil scientists, but perhaps the cruelest is a creation herself. Android 21 emerges in FighterZ as a forgotten product of Dr. Gero. She was inspired by Majin Buu, meaning she has an insatiable appetite.
That's why she creates an army of Z-fighter duplicates. Until she can find the real deal, she absorbs these copies' energy by turning them into candy and eating them. Yes, she creates life just to consume it.
Android 21 isn't out to conquer the world, build the perfect warrior, or battle a worthy opponent. She's just hungry. Not only is that ludicrous and funny, but it's wonderfully creepy. It goes back to the animal fear of becoming prey, making Android 21 a more elemental enemy than most Dragon Ball baddies.