Vocaloid Nise box art

I tried to draw and color Nise( Megamine, my fan-vocaloid) like she has her own box art. Used Miku's box art as reference, mostly the angle of the pose and head shape.
I don't know what number/other to put on her arm.

Why does this(coloring) make me think of Super Smash Bros. Brawl?! =_O?