Honestly, there's no reason corrupt has to equal murderhobo. Have any demons even murdered anyone in-game? Kas hasn't other than her backstory IIRC.
Let people be a dick. Where we are now, basically my corrupt PCs are only corrupt because they let the wrong people cum in them. Let me manipulate people, that would at least explain why I'm marrying all these horsepeople I'm not attracted to: to quietly consolidate power throughout the Marches. All I need is to get the Minotaur king hooked on this pussy and pretty much the entire map is mine.
Or even just let me have a spine more often. Sorry Kiyoko, I only fucked you because your god guilt-tripped me, I'm not into you like that, back off. Hey every Marked Merc I see in town sometimes, stop fucking attacking me in the foothills, the fuck is your problem? Next time I'll make it so your uterus isn't the only malfunctioning part on you. Hey Alraune that I ostensibly control, get your kids to stop ambushing me or I'm gonna have to start weeding. I could go on.
I grew up playing Ultima. From IV on, you were the Avatar of virtue, the most righteous in the land.... and every game still let you rob the bank, rip off blind shopkeepers, lie for your own convenience, and murder Lord British for funsies. You could easily get a spell to wipe out all life. Sure, you ain't gonna beat the game that way, and some of your actions would make your party turn on you, but you could do it. And it was awesome.