We've all done horrible things in videogames. Let's not lie to ourselves. I mean, some games are flat-out designed to make you do horrific acts. But these people have problems. These people took things a step too far.
Become a savant so people will follow you with out question, take them to a cult and sacrifice them. Go back to town, buy their property, repeat till you're wholly evil, raise the taxes on the property to exorbitant levels, save game, advance the time on the Xbox 20 years, come back and rake in that sweet dough. Donate like .001% of it to the church to become holy again.
Zoo Tycoon. I played properly. Built a super popular zoo. But the catch was... it was only carnivores.
I fired all the zoo keepers. Blocked off the exit, and deleted a piece of each and every exhibits fence, one by one. Sat back, and enjoyed.
In Pokémon Silver, this one kid asked me to hold onto his Shuckle for fear that some people were gonna steal it from him or something. After I defeated those people, he thanked me and asked for Shuckle back.
I didn't give Shuckle back.
Maybe not the MOST morally corrupt thing, but the only one I feel kinda bad about.
Legend of Zelda: Breath of the Wild. I need to collect all these chickens, but some old lady won't let me into her plum tree garden because what if I DAMAGE her PRECIOUS trees? These trees were her only reason for living!
So I'm pretty pissed off about this, because I just need to grab the chicken it's RIGHT THERE.
This game gave me infinite magical bombs, so. I toss one into the garden and detonate, mostly out of idle frustration.
A bunch of trees are destroyed. The old lady yells at me.
So I keep doing it, because if all the trees are gone, theres no reason for her to chase me out of the garden, right?
Finally all the trees are gone, and this old lady basically says "oh... I've got no reason to keep living..." and waddles away slowly, presumably to kill herself.
I think to myself "this seems really dark" and google the chicken/plum tree puzzle.
I was meant to wait until night time, when she would go to bed.
I destroyed this old lady's soul for a chicken.
In Fable 3, I married a woman to have a child with her for the achievement. I then killed my wife, which sent my kid to the game's orphanage, which I later had converted into a brothel.
Civ IV, I like to turtle so I'll do my own thing, researching and building wonders. But when some asshole like Montezuma declares war and raids a couple of my cities, I raise a giant army and counter attack. I don't capture his cities, I burn every last one to the ground. I don't want anyone to remember that he or his people even existed. Then I send out settlers to establish new cities on the burning ruins of his forgotten ones.
I endorsed all the shops on the Citadel as being the best shop on the Citadel in Mass Effect 2.
My nephew beats pigs to death in Minecraft with the raw pork he gets from the previously killed pig. He does this for hours.
Edit: A bonus- his second favorite thing to do is ride the horses off of cliffs so they die from fall damage. I swear he's a nice kid.
When I play high chaos runs in Dishonored, I make horrific displays of the dead bodies. I think the most fucked up one was when I killed a veteran guard in his office, & he ended up cut in half at the waist. I propped up his torso in his own desk chair, & placed the legs in the "guest" chair across from it.
Back when I played WOW they used to have this orphan event where you could get an orphan and show him around the world. The first year, or maybe even only the first couple of days the kid could draw aggro and get beat on by the monsters in the area.
I used him as a distraction to loot and pillage while the kid was eaten by a variety of monsters.
Fallout New Vegas. I opened Mr. Houses containment chamber, dropped a bunch of food and mushroom bits in, then closed it again. Sealed in the flavor.
I'm sure his excellent immune system had fun dealing with that.
Roller Coaster Tycoon. Gather all the unhappy guests. Drop them all into water. Wait until everyone had drowned but for one survivor. Put him on his own special 1x1 island. Repeat until I have many survivors. Drown them, again saving the lone survivor. Repeat for generations.
There used to be a mod for the game Minecraft where you could run villagers into a grinding block and it would spit out meat and emeralds. You could then eat the meat that you produced.
So murder in a dragged out and awful way followed by cannibalism.