Need opinions,suggestions and feed back

[Naberius The Slayer]

Opinions needed!!!
I have been working on a rpg story of mine for quite some time now.Trying to get it to where i'm satisfied with the ground work before I set it out for everyone to join,I want to try to get it to where it will be a great rpg like tides of darkness that i've been a part of for some time now.
However I do wish to perhaps have a mini review by you if you have the time, and also how would I go about starting this when I am ready.First i'll give you a bare skeleton of the working overview so far, I realize I may be pushing the envelope with it but I do wish it to come out right.

The rpg story that I am working on will be a very dark and foreboding one,the world it will be set in will be within a city that will be somewhat like a gotham but not you know? I'll be placing it within the lines of gothic/horror/mystery/thriller catagory.A main chericter will be that of a man(sort of) that I have put alot of creativity and energy in.He will be known as The Dementor, a very dark and psychopathic seriel killer.He will have very strong ties into the occult, and is rumoured to not be very human.He targets young women that share something in common,but what that is exactly is unknown.His pursuers of course will consist of a special branch of homocide detectives, and an oddball branch of field occult reasearchers called The Lantern Branch that are dedicated to seeking out those with true occult power and subduing and researching them as specimens.
I will not be holding back on this unless asked to do so,in this story The Dementor in my head i'll set free and yes there will be slayings in detail in this.I wish it to have impact on the rpg realm, review this and please let me know.
Thank you for your time