One of my first 3.5e characters was a Tiefling Rogue, and honestly I kinda like the concept that went into him. So much so that I'm actually looking to re-make him in a slightly better fashion than vanilla Rogue so that he can be playable in higher-tier games. Here's some of what I'm looking for:
1) Dex- and Int-based: Good (6 or 8) skill points per level early on with good starting Int. At later levels it's not as important to use classes with high Skill Points. These two ability scores are going to be what any given character does best.
2) Minor casting ability: I've looked at the Shadowcaster, and can see a lot of potential there. Getting 13th-level Shadowcaster capabilities and then picking mostly Apprentice and Initiate powers looks like a good way to go to get lots of cool abilities that fit with the character. That said, mid-level Beguiler casting and/or Lesser/Greater Warlock invocations are also a way to go. Sorcerers and Dread Necromancers are right out because they're Charisma-based, and I want to avoid too much MAD. Wizard and Warmage are out because they don't fit at all thematically.
3) Decent melee capabilities: I think the most appropriate combat feats for this character would be Dodge, Mobility, Spring Attack, Bounding Assault, and Elusive Target (if possible, Rapid Blitz isn't a terrible addition), and I'd also like to be proficient in the Shortsword, Rapier, or a similar exotic weapon (which will be made Feycraft to allow for Dex to attacks). Picking up a few SA dice for stuff like Craven and Staggering Strike would be nice as well. Ideally there will be something in my spellcasting that augments my melee attacks, too, although that's not needed.
4) Some kind of demonic tie-in. Hellbred race is one possibility, as is Tiefling or Lesser Tiefling into Half-Fiend progression, although the latter seems to be pretty weak without LA Buyoff.
I was initially just going with a Swashbuckler/Rogue using the Arcane Stunt ACF, but that technically disqualifies the character from being able to take the Daring Outlaw feat (although I suppose I could ask a prospective DM for a houserule on that). I also thought of Warlock/Rogue, but I can't think of any PrCs or feats that would make that sort of combination especially useful. Afterwards, I started looking at some sort of Rogue/Shadowcaster and thought about a potential Keeper of the Cerulean Sign build refluffed to be anti-Demon instead of anti-Abberation, but that would not only require houseruling to get into, but also seems to be way more spellcasting-oriented than I think I'm willing to go with.
So yeah, I'm just having a hard time putting together one solid build. Any ideas from the CO folks?