Quite nice. I like the style you used to draw these three; simple but quite detailed. Although...Now I'm getting Sonic Heroes vibs from looking at this picture, so... SPEED = Bass: that dash of his and he is one of the fastest of the trio I think FLIGHT = Rock: One word...RUSH! POWER = Blues: Dat shield can take a lot of punishment and dish it out. I almost picture Proto Man as kinda using his shield offensively too. Could you imagine getting smacked by that thing with the strength of a robot behind it...OUCH!
I kinda want Duo in the back, but too bad he was only the fourth member in Power Fighters. I would enjoy seeing another version with all the animals, ie Treble/Bass, Tango/Proto (I blame the manga), and Rush/Mega.