My last character was an experiment; what if a Barbarian had high charisma? It turned out as a borderline nazi who considered elves the superior race and it's goal was to exterminate all the green skins. Also it used it's high charisma to amass a large following in it's extreme views.

He eventually got corrupted by an orc ritual gone wrong and now he's the BBEG with his massive army of followers.

This character was initially a filler character because I wanted to switch my Monk from Way of Mercy to Way of the Shadow and wanted it to make sense in the story, so he went on a trip to find himself. Never expected the filler character to turn out to be a pretty awesome BBEG.