Board Thread:Off-Topic Discussion/@comment-30602727-20140827000707/@comment-3076833-20141015030735

"2P" derives from the colour alternations Hima did for the nyo axis and allies characters (as well as regular axis). The name 2P is fangiven but derives from fighting games such as brawl where characters have different "colour palettes" so you can differentiate 2 players who have the same character. Fandom seems to give them the opposite or dark/edgy personality mostly because said colour alterations are dark in the official, not to mention they were drawn with more "evil"-ish faces.