Okay, I've developed some new ideas which I've added to the list below. These are just some suggestions. If anyone has any particular ideas of their own feel free to contact me with them. My list of On/Offs is in my signature.
Each of these ideas would have me playing the male character described and where appropriate a dominant role.
Shapeshifter (M/Any): A shapeshifter takes on the appearance of someone's lover and visits them while their lover is absent. This scenario is open to a wide number of different options, it could be a more subtle psychological piece where the partner finds out afterwards that it actually wasn't their lover, or perhaps their lover is dead and so couldn't come back (is it a ghost?). It could be more of a kinky scenario where perhaps the deception is revealed partway through. This could range the gamut, so I won't flesh it out any more until I can discuss it with someone interested.
Paradox (M/M): A time-travel story. A man with the supernatural ability to travel through time and space goes back a decade or so to when they were a young man to teach them of their abilities and also seduces the younger version of themself. They are travelling back to this time and teaching themselves this way since in their memories that was how they learned to time-travel.
Questioning (M/Any): This idea is a bit of a twist on an old classic. The police arrest a male criminal and a cop (male or female) finds themselves attracted to them. However the cop is a submissive and offers themselves completely to the prisoner. Might contain some reverse bondage with the prisoner chained up but the police officer following their orders. I think it'd be fun to reverse the standard roles in this sort of arrangement. Also I've been interested in trying a bondage situation with the dominant partner tied up.
Invisible and Inevitable (M/Any): An ordinary person starts seeing a man around everywhere, as though they're being followed. They soon discover though that no one else can see or interact with this man and even the ordinary person can only see and touch this man when the man wants him to. At first he just watches the character, but soon he starts feeling them up and then more.
Shapeshifter II (M/M): A shapeshifter is jealous of the luxury life that a rich man experiences. He takes on the shape of the man, abducts him and takes over his life leaving the man prisoner as his sex slave.
A few screws loose (M/Any): A geek working on the cutting edge of robot research (or just a crazy mad-scientist or young prodigy if you prefer) struggles with long hidden sexual fetishes which they could never find ways of unleashing. Finally they decide to build the perfect man for them, submissive and interested in all their kinks and fetishes. Things go wrong though when they turn the robot on and it decides it doesn't want to be the submissive partner. It overwhelms the geek and forces them to experience all of their kinks, from the other side of the fence.
Beastmaster (M/F): In a vetinary science class there's one student who is a bit strange and largely unpopular but exceptionally good with the animals. In actual fact they have the psychic ability to communicate with and control animals. He asks out one of the more popular and attractive female students who shoots him down and makes no effort to spare his feelings. As she's walking home late at night she hears a dog howl and then another, she's soon chased down by a pack of the local dogs in the area. When she's cornered the psychic reveals himself and claims her as his prisoner. This story is rated extreme for containing bestiality with non-sentient animals.