ok, my ideas so far (don't have 4CtF yet, going to try and get it tomorrow):
Mantis
A ninja connected to a Japanese tech firm, he goes around dressed in black (think the vampire commando squad from Blade II; that kind of uniform) he uses swords, guns, James Bond type gadgets, and a pair of rectractable blades on his forearms that are parallel to the plane of the back of his hand (these are tech/gauntlet pieces, not Wolverine implants). Seeks revenge on the enemy who killed his father, the previous Mantis. This enemy is one of seven other 'heroes,' all named for a different animal (think kung fu forms here, Dragon, Tiger, etc.).
Blue Sentinel
An Iron Man type armor suit hero. A rich businessman/thrill-seeker who had tried everything else and decided to fight supervillians for kicks and more death-defying thrills. His suit is lithe and quick, optimized for speed, with strength secondary and an energy blast third.
The Supreme Intellect
A scientist who developed extreme use of memory and speed of calculations, and through some immense stress (he won't reveal the exact process) broke through into a higher plane of ability. His powers are all driven by pure thought alone (not telepathy or telekinesis). For example, he might have a 'teleportation' power that works by him being able to recognize and conceive of higher dimensions (with the same ease that we see three or less dimensions), calculate their mathematics, and 'step through' them. Teleportation is one thing I thought of for him, some kind of 'thought shield' that deflects attacks was another. Mostly I want him to have powers like being able to calculate faster than computers, and other consequences of having super-powered intelligence. I see him as a Smart/FieldScientist/Hero.
I'm trying to think of at least one more possibility, but I'm strongly leaning towards the Intellect right now. Note that the names are changeable - I just threw something in there (aside from Mantis, who's an old character). I'm thinking more about the character concepts right now.