I know my thoughts (and tastes) are kind of strange, but I think some under-used ideas that could be pretty interesting (just because you don’t see them much, if at all, might be like:)
~ The main character genuinely being an eldritch abomination. Thought patterns that make normal human (or whatever race) characters go “Hmm… I just don’t get it.” or some such. A horrifying, unrepentant, genuinely sadistic and evil being of alien geometry that it can make other people go “If someone is so far removed from human thought and morals, are they truly evil?” Despite the main character being downright, horrifically evil. (I have a thing for well-written villains-- and Lovecraft-inspired eldritch nightmares.)
~ Somewhat in the same vein, a main character inspired loosely by both Kefka Palazzo and Revolver Ocelot (when the latter was young and interesting.) Unapologetically evil, extremely intelligent and deadly, arrogant, egotistical, flamboyant, rude, betraying others when it suits their needs, ruthless, sadistic, scheming, manipulating, dishonest, but friendly, playful and pants-shittingly mad enough that nothing they say or do is an empty threat.
~ I also like the idea (in a fantasy setting) of having the MC being a poisoner (perhaps a courtly one) and one of the ROs being a torturer (probably working for the same court.) There’s something about such a pairing in a traditional fantasy “court of debauchery” setting that I find very appealing.
~ There are a lot of games (not just IFs,but games) where roguish characters are present. Rather than having the MC be some sort of “noble” Robin Hood-style thief or “assassin with morals,” why not have the MC be a genuine rogue (Enough with the Chaotic Good/Chaotic Neutral at best rogues!) who is greedy, selfish, out for themselves, vain and having many vices? (Drinking and gambling are not vices, not really.)
~ In the same vein of the MC being a true rogue, why not something else you don’t really see-- they could start as a bandit/brigand who is just trying to do what they do every night (try to take over the world!) make a quick buck by attacking travelers. They’ve got room for character growth and development, but they aren’t interested in changing everything about themselves. Maybe starting an IF where said bandit/brigand is captured by guards/mercs/whatever and has to figure out how to escape from prison/the dungeon before they’re hung?
I could keep throwing non-heroic, character ideas out there, but that’s probably not what a lot of people want to read, espeically since this post could end up getting very long. XD
What about races? We see humans, elves and fey creatures a lot. There are many fantasy races that I haven’t seen used all that often, that could possibly make for some interesting MC racial possibilities:
Gorgons (not the bull, the Greek snake-haired, clawed, poisonous people who could turn others to stone with a glance), harpies, half-orcs (I think I’ve seen orcs/half-orcs maybe three or four times, maximum?) Dwarves, dryads, alraune, nagas, gnomes, Drow! (Don’t get me wrong, your average elves are great, but I’ve got a soft spot for Drow!) Driders, mephits, rakshasha, even the many kinds of Djinni (ifriti, shaitan, marid, et cetera) could be pretty interesting to see every now and again, I think. ^.^
Horror is also pretty under-done, I think. (Not supernatural horror, that gets pretty old-- definitely no more zombies, werewolves, or vampires.) Slashers, well-done psychological horror, serial killers, eldritch horror, kidnapping/abductions (that aren’t mystery, but horror/crime-based) could be pretty fun.
A prophecy gone wrong could be prettty interesting, I think. Rather than being another trope-ified “chosen one” intended to save the world, what if the MC was the chosen one-- cursed by whatever pantheon to bring about Ragnarok/whatever apocalypse?
Instead of being able to romance a crime lord (in any setting) why not have the MC take the role of being the leader of a crime syndicate?
I also think something truly apocalyptic (Think inspired roughly by Wastelands, Fountain of Dreams, Meantime, Fallout 1 or Fallout 2) could be a hell of a lot of fun!
So could a truly dystopian setting (use 1984 as a reference for that X3) or even Kafka-esque would be pretty interesting and entertaining. 