Probably best I don't get involved... I would side with Sega.
That's what Puyo Puyo thinks too (at first). She always won the championship so she got bored playing and thinking joining the "evil" SEGA could be more interesting.
At least Anode version though (and her thinking way was of course of being corrupted), Cathode version just really loves to beat people (both in Puyo Puyo games and in Virtual world)