This is an idea I've been thinking on which I'll put down next but basic nutshell is I'm looking for a solo supervillain game, more plot heavy then smut heavy. Also willing to use a system but that's not required.
Henry Collins always did love Halloween when he was a kid. A genius growing up in Nebraska, his parents weren't abusive but they were a bit too strict on their kids - except on Halloween. Then they'd cut the leash a bit and Henry could have some fun. His freedom, coupled with his engineering talent, made his Halloween pranks the stuff of legend in his home town. It's when he went to college that Samhain would truly be born.
Moving out and free on his own, Henry studied hard and would eventually earn a double MS in Electrical and Chemical Engineering - but on Halloween he'd cut loose and enjoy himself. To hear the frat row describe it, one year he even managed to fake a zombie apocalypse for one of their parties. However, one of the frats had rumors of occasionally drugging and raping girls from the sororities around them. The Halloween of his Senior year ended with some real horror when Henry accidentally drank one of these drugged drinks instead. Even worse, he discovered that the school knew about the incidents but a couple admins were covering them up.
Samhain was born to get some payback - he really did have the good intentions when he started. A "Halloween Spirit" would haunt the campus then, using pranks and thefts to expose what they were doing. He even robbed a bank once to get at hidden connections, and he happened to walk out with a ton of money as well. After that he was sort of hooked.
By day Henry Collins is a freelance engineer, making most of his legit money on special effects contracts for theater companies with the occasional haunted house job. By night though he is Samhain, a thief and prankster "spirit" that uses halloween/supernatural themed technology. Holographic "Costumes", mag-lev "witch brooms", robotic "black cats" and "imps", "candy" lockpicks, etc. He's definitely a villain with how much stuff he's stolen and some of the pranks he's pulled, but he's far from the worst. He's even rumored to surprise kids with candy in full Samhain gear on Halloween sometimes.
The big adventure begins with his latest bank robbery when Samhain takes a few safety deposit boxes. The contents of one of them however proves that a major superhero is actually deeply involved with a human trafficking and slavery ring, and Samhain has to play for stakes bigger then ever because if he loses too badly he could lose his life...