This was well drawn, true, but i feel the shadows seems a little, wrong, on Pikachu. I'd think his shadow would be more to the left, and possibly a little larger. Also, Pikachu's eyes seemed to appear a little hem; different, he seems almost sad, which makes him not fit as well. As for originality, you defiantly win on that. The concept makes me think of a gang somewhere in the underground of China or something to that extent. For Raichu, his pose in this makes me think back, in a good way, to the original Pokemon series, and it seems to emphasize his physical prowess in the position of the muscle of the group. And the ever-adorable Plusle and Minun... I unfortunately don't see them as the roles you gave them, but then again, i never watched the series in which they came in, so I cant speak to heavily for or against them. And lastly, Pichu. I like him in general. He seems to be like a skirmisher, which emphasizes his agile form in the show. Overall, I'd say you did quite well on the majority of this fine fine work, I rate you an 8 1/2 out of 10, and will show your work to my friends as soon as possible!
Looks like Squirtle squad has some competition. LOL. I find Minum's little knife kinda cute. He's probably gonna throw it like a ninja star. Also, the face on Pikachu's face is priceless. Do more Pokemon Mafia/Gang fan art. Keep it up!