The difference between Canon of Creation and Vengeance in Shin Megami Tensei V Vengeance and where to start

You heard it right she is a playable character but she looks actually fun thanks to this trailer:

http://www.youtube.com/watch?v=lBoL1Ic9uWw&list=PL2JiZAV5BmDU_nJylD2zvyHvgFm9Ot8Nr&index=1

First I was like "What the hell?" but after this trailer LOL! She looks fun to play as (be ready for incoming wii fit girl online pro's).