nonono do not drop any supporters. You only have 11! AND ONLY EIGHT DRAW!
~Alright, you should drop 1-and only 1- Terrakion. 5 Fighting attackers is plenty and starting Terrakion makes it a bad day (sort of). Terrakion is necessary in this deck because it is a Fighting deck and Landorus does a so-so job of defeating Darkrai by itself.
~Now you should take out two Fighting Energies because 9 is too many and you need room for other things.
~Keep the third Twist Mountain and take out all the Skylas. In a speedy brutal beatdown deck like this, straight aggressive draw is best.
~Take out the Potions, no point. You aren't bad against spread/snipe anyway and without the Skylas they are mainly dead cards.
~Take out all the Exp. Shares. They will be replaced with Energy Switches here in a moment. Energy Switches are superior because you will not need the Exp. Shares much anywya and it is such a pain in the butt when they are Scrappered.
~No need for Tornadus EX either, you have no reason to waste deck space on a Fighting counter.
~Take out Gold Potion, Computer Search outclasses it so superiorly in every way it is a waste not to have it. If you're going to give the complaint: "I don't have any", I'm just giving advice like you wanted and you didn't mention being on a budget. So if you can add in Computer Search in place of Gold Potion.
~ Take out two Heavy Ball for two Ultra Ball, you're going to be glad you did so you can search out the Mewtwos and Aerodactyls and the Bouffalant I'm adding in.
Now for additions, we've got 11 slots now.
~ Throw in 4 Energy Switches, they're very good and even more helpful because you run 4 Switch. Very good synergy with Mewtwo and Terrakion and your opponent will not see it coming like with Exp. Share.
~Let's be honest, Shaymin EX screws this deck hard. Throw in a Bouffalant DRX.
~ Aeordactyl is wildly inconsistent but we gotta at least try. +4 Old Amber Aerodactyl.
~ Now lets take out an Eviolite so we can have more room for Draw. How about +3 Random Receivers.
Well, that's 60 cards. If it were me, I would take out all Aeros and Old Ambers and Twist Mt.s, but I'm not sure you want to do that. Let's just say you did for a minute...
- 3 Twist Mountain
- 4 Old Amber Aerodactyl
- 4 Aerodactyl
+ 4 PlusPower
+ 1 Super Rod
+ 3 Tool Scrapper
+ 1 Random Receiver
+ 2 Bianca
You don't have to do that bit at the end there but I think it would be best to ditch Aerodactyl as a whole.