Phantom 4 is right, Band Mewtwo seems pretty outclassed. You might as well run Scarf Mewtwo, so you can screw Blissey with Trick while being more useful.
You should have Roosted before KOing Giratina... :0 That was the only huge gameplay flaw I noticed. Interesting battle, though.
Also, Ho-oh is Japanese, not Chinese. Dx LOL.