I tend to avoid excessively "evil" or demented characters, typically because they don't fit with the rps I join. The one that sticks out the most to me was a character in a GoT rp from a while ago. He was the young lord (17? 18?) of the Skagosi. Their liege lord, House Stark, recently had the audacity to mention that they should start paying their taxes. My character responded by raiding some small villages, taking prisoners, then (off scene mind you) raped them as part of a ritual which ended with some cannalbization. Maybe a dozen or so men, women, and children that were captives. He also kidnapped one of the Stark girls, leading to her impregnation. It was a bit over the top, but the North called for a big baddy that wouldn't be all that hard to take out. Plus, lore-wise, the guy fulfilled the boogeyman aspect of his people. He was crazy, even for them, and probably wouldn't have lasted much longer.