Cool. I just wanted to figure out how it would work first. You'd need a LOT of gore and disturbing imagery, and we'd have to make rules and the basic plot, because we'd need interaction. If anyone can get up a bio (i don't think we really need a template, it's pretty flexible.), that'd help by knowing our characters first.
Edit: Added one of my OC's. I think he'd be the easiest to come in as he would have a reason to be near the others.
Name: Enigma
Appearance: A tall man in a dark grey trench coat, long baggy trousers and a dark grey balaclava (but there's no holes for mouth or eyes). He has polished, shining pitch black shoes and has a long frayed black scarf wrapped around his neck. On the mask, he bears an extremely accurate drawing of his own brain, graffitied on in a dark blue paint. (It basically is where every part of his brain would be, but on the mask)
Weapon: No particular weapon, whatever he has access to or is necessary.
Powers: Seems to be almost omniscient.
Backstory: None really know anything about the one referred to as Enigma. You'd be hard pressed to find any evidence of his existence, and the people
who would probably be able to tell you about him are long dead. The police have been keeping tabs on related murders however. Seemingly random kills. All around the world. No seeming correlation, if you didn't check the criminal records of his victims. Not small time criminals, no, but serial killers. Some of the most dangerous and unhinged people around, that the police were struggling to find. A few were even killed in police custody, or placed somewhere they could conveniently be found. All different ways. Arson, blades, blunt trauma, choking, gunshots, even poison. The only consistent factor is the infamy of his victims, and the graffiti sometimes left on their bodies, sometimes on the walls, sometimes on the floor, even drawn around their corpse. Exact recreations of their insides at the time of death, masterpieces in his eyes.
