Celebi Mewtwo - zanderson257

2 Mewtwo EX 
1 Shaymin EX 
1 Regigigas EX
4 Celebi Prime
2 Tornadus
1 Shaymin UL

Pokemon = 11

10 Grass
4 DCE

Energy = 14

3 Skyarrow Bridge 
2 Eviolite
4 Pokemon Catcher
4 Junk Arm
1 Lost Remover
4 Dual Ball
1 SUPER ROD
2 Switch
2 Pokegear 3.0
4 PONT
4 N
3 Professor Juniper
1 cheren

T/S/S = 35

Strategy

The starter in this deck is celebi, which lets you attach one more energy from your hand per turn.  This helps power up Mewtwo on the bench.  With the use of skyarrow, you get free retreat with celebi, meaning that you don't have to rely on a switch or lose the energy to get back to the mewtwo.  Tornadus is a great attacker for this deck as well since it can push an energy back to the bench while attacking.  You also don't lose two prizes when it gets KO'd like you do with a Mewtwo.

Pokemon Analysis

I'd suggest swapping the Regigigas EX out for another tornadus.  Tornadus is often the preferred attacker since you don't lose two prize cards when it's KO'd.  It's free retreat with skyarrow easily allows it to get out of the way and still save a DCE that may be attached to it.

Energy Analysis

What you have looks great, but if you find you need one more card in the deck for something else, you'll probably be safe going down to 13 energy.

Trainer/Supporter Analysis

Most of your list looks great, but I wonder where the collectors are.  Since everything in this deck is basic, a collector essentially gives you whatever you need (as far as pokemon of course). Dual ball is great, but too flippy to leave collector out completely.  To make room for it, I'd drop 2 dual ball and 2 N.  Since you can't exactly live off the field or recover from a bad N (like Magnezone or Reshiram decks), relying too heavily on N could hurt you just as much, if not worse, than your opponent.  Everything else looks great!

Overall

You have a well built deck already, so I don't really have many suggestions to make to it.  I hope what I did offer helps you out a bit!  Good luck at States!