For some rulers, it's not enough that they control a vast dominion. They also have to treat their subjects as though they were constipated grumps with no sense of morality. Hence came forth the usual and favorite villain stereotype in media, gaming included: the evil tyrant. Granted, there's no "good" tyrant, but some of them in gaming are too difficult to like or appreciate.
Their crimes range from bringing multiple apocalypses to a plethora of human rights violations that even their followers just can't ignore blindly. In hindsight, they make for a good storytelling element. Players not only get to enjoy and justify their rebellious gameplay, but they also get a good metric of what behavior to condemn in a leader.
8 Diablo – Diablo Franchise
Diablo has existed in many forms and iterations in the many Diablo games out there and all of them have one thing in common (apart from the name): he's a walking apocalypse trigger. He's one of the quintessential dark lords in gaming. As the supreme ruler of Hell in the Diablo mythos and the Lord of Terror, Diablo's crimes are too many to count and too heavy to weigh.
While he also wants to rule everything — including measly humans, Diablo and his brothers do it in a painful and macabre way, often corrupting their victims and turning them into soulless husks and depraved vandalisms of their former selves. If that's not enough, Diablo and his brothers also want to change reality through the Worldstone.
7 Chaos Gods – Warhammer Franchise
If there were demon gods that could make Diablo look like a lost puppy in comparison, then those would be the four gods of Chaos in the Warhammer mythos. Each one of them represents a domain or aspect of corruption: Khorne is the Blood Good who rewards violence and anger, Slaanesh is the Lord of Pleasure and Excess, Nurgle is the Plague Lord and loves disease, and Tzeentch is the Lord of Change and deception.
Each of them also enacts and rewards their own forms of corruption among their followers. Needless to say, they're behind the struggles, deaths, and suffering in the Warhammer mythos. Those who want to avoid these hardships by joining and serving these Chaos Gods are in for a surprise as these four deities can be just as cruel to their followers as they are to their victims.
6 Pontiff Sulyvahn – Dark Souls 3
Speaking of tyrants who love slavery and suffering for their victims and followers alike, Pontiff Sulyvahn takes the evil crown among all Dark Souls tyrants. He's the worst out of all of them. He ruined his own kingdom — and that's still pretty common among Dark Souls rulers who fell out of grace.
What makes Pontiff Sulyvahn worse is how he forced all his subjects to become grotesque mutants and to serve an ever-hungry god named Aldrich. It just so happens that Aldrich prefers prey to prayers, and demands regular sacrifices to keep himself fed. It was Pontiff Sulyvahn and his lackeys who kept Aldrich fat with a mountain of sacrifices.
5 Pagan Minn – Far Cry 4
Moving on to something more relatable in a real-world context, Pagan Minn from Far Cry 4 is a haunting parallel to many modern-day tyrants. He's the mad dictator of the fictional country of Kyrat, which is a bootleg video game version of Nepal. Players get to see Pagan Minn's atrocity firsthand. He tortures innocents and shoots innocents on a whim.
To make matters worse, he's quite unpredictable with his fits of insanity. Even worse, he surrounds himself with equally wicked and bloodthirsty cronies with whom he also grants massive military power. Pagan Minn did just about anything to keep Kyrat in its destitute, war-torn third-world country status. He even changed Kyrat's currency just to ensure that citizens with monetary savings remain poor.
4 Dogeyes Lin – Sleeping Dogs
Again, he's a tyrant who operates on a smaller scale. This time, it's a Triad crime lord named Dogeyes Lin from Sleeping Dogs whose transgressions in the crime underworld make him a turbulent threat even to his peers. Some of his worst crimes were drugging prostitutes and forcing them to work in a never-ending cycle to fund their amphetamine addiction.
Of course, there's also the usual Triad stuff like torture by mutilation, human trafficking, and extortion. Even the other Triad crime lords were not fond of him due to his dishonorable and twisted methods of earning income for their organized crime group. Of course, if that wasn't evil enough, he also dabbles in drug manufacturing and trade. It's like he has a bucket list of all possible crimes.
3 Adolf Hitler – Wolfenstein Franchise
The Wolfenstein series (both the original and the remakes) took everything that the world knew about Hitler and turned him into a more evil and sick despot who won World War 2 in an alternate history. So just about all of real Hitler's crimes are also included and amplified in these games. That includes eugenics, racial purges, massacres, forced labor, mass sexual assault, and many other war crimes and human rights violations.
Then, they imagine how an older Hitler would behave as seen in Wolfenstein 2: The New Colossus. There, on top of the psychological burdens of his massive crimes, Hitler also has some frequent psychotic fits and would shoot people in the head just because he can.
2 Rodrigo Borgia – Assassin's Creed 2
Some of the worst kinds of tyrants are those who have managed to convince or fool their servants of their innocence. A wolf in sheep's clothing per se, and among those, Rodrigo Borgia from Assassin's Creed 2 is quite deplorable. Through murder and deceit, he abused the power and privilege of being a Pope in order to secure both Rome and the Vatican as his seat of power.
Borgia practically turned all of Renaissance Rome upside down and robbed it of its immediate future just to maintain power for himself and his children (Cesare and Lucretia Borgia, later on). He's also a member of the Templar organization, which seeks to enslave and control all human beings, though Rodrigo didn't need that push to become evil.
1 Saburo Arasaka – Cyberpunk 2077
Arasaka has always been portrayed as the corporation not just in Cyberpunk 2077 but in all of gaming as a whole. This is a mega-corporation that treats human lives like an asset that's cheaper than money. Led by its functionally immortal magnate Saburo Arasaka, the company toys with the idea of immortality by preserving a person's brain and using live, organic bodies to essentially transfer souls.
But Saburo doesn't just use it for immortality. He also uses this technology on his enemies in order to deny them the peace of death. By preserving their consciousness, Saburo gets to eternally imprison whoever he can. When one thinks about it, that's worse than slavery. Saburo Arasaka essentially controls a person's soul like some kind of cyber Devil.