Hello! I really like this idea, however, I think you could make a few adjustments to make this deck run smoother.
Personally I would get rid of the Dedenne, as you could start with it, and It's main attack: Energy Short is only really useful against Yveltal-EX. Entertainment is a cool option though.
I think it would be an interesting idea to tech in a 2-2 Weavile line from Steam Siege. You could throw down some Muscle Band's on Latios-EX to try a turn one donk, and then use its ability to bring the Muscle Band to your hand, place down Latios Spirit Link until you evolve, and then put down Muscle Band to boost your damage by a little bit.
I notice this deck doesn't run Shaymin-EX. Unfortunately, this card is necessary for most decks to run smoothly, so I think you should put that it. You could add in a 1-1 Octillery line if you can't afford it, it would be better if you could throw in a 2-2, but that could clog the deck up a bit.
Here's what I would change, and then I'll explain why.
-1 Golbat
-1 Dedenne
-1 N
-1 Giovanni's Scheme
-1 Delinquent
-1 Xerosic
-1 AZ
-1 Sacred Ash
-3 Super Scoop Up
-4 Puzzle of Time
-1 Psychic Energy
+2 Weavile
+2 Sneasel
+2 Shaymin-EX
+1 Ninja Boy (Personal Preference)
+3 Devolution Spray
+2 VS Seeker
+2 Special Charge
+1 Trainers' Mail
+3 Muscle Band
I removed the Golbat and Dedenne, as you could use those cards in better ways, and the changes I'm suggesting are trying to make the deck more constant, and having a 3-3-2 line of Bats makes the deck more inconsistent in my opionion. N, Giovanni's Scheme, Delinquent, and Xerosic were removed as their kind of gimmicky supporters, and those spaces can be used better. Plus with the addition of more VS Seekers, you can bring out some of the supporters you want out faster. If you choose AZ or Ninja Boy is up to you, I would use Ninja Boy to prevent Shaymin, Sneasel, or Zubat starts, but AZ allows you to reuse Bats and pick up damaged Pokemon. Sacred Ash is a luxury card, and can clog up your deck, as your not trying to discard Pokemon, in decks like M Gardevoir-EX (Despair Ray,) M Rayquaza-EX, and Night March, it's useful as your either discarding Pokemon, or you need a lot of Pokemon on your bench. Super Scoop Up can be replaced with Devolution Spray for more efficient results. Puzzle of Time is better replaced with other cards that shuffle cards back into your deck. You won't want to be attacking with anything but Latios-EX or M Latios-EX, so Psychic energy is unnecessary, you could work fine with 11 energy cards.
I already explained why the Weavile, Sneasel, Shaymin-EX, and Muscle Band are good choices, but I'll explain the others. With Devolution Spray you can devolve your Crobat's and Golbat's, and you don't have to wait a turn before you can start placing down damage counters again, again personal preference, as you could use Super Scoop Up if you want. VS Seeker's just make most decks constant, so it is a pretty obvious choice in my opinion. With Sonic Ace discard energies, presumably Double Dragon Energies, you can use Special Charge to shuffle those back in your deck. Trainers' Mail speeds the deck up quicker, and is becoming a necessity for most decks to set-up quick. That's what I would change.
Here would be your new Deck-List:
M Latios-EX/Bats/Weavile
Pokemon (19)
3x M Latios-EX
3x Latios-EX
2x Shaymin-EX
2x Crobat
2x Golbat
3x Zubat
2x Weavile
2x Sneasel
Trainers (30)
4x Professor Sycamore
1x N
1x Lysandre
1x AZ/Ninja Boy
4x VS Seeker
4x Trainers' Mail
4x Ultra Ball
3x Devolution Spray
2x Mega Turbo
2x Special Charge
1x Escape Rope
3x Latios Spirit Link
3x Muscle Band
Energy (11)
4x Double Dragon Energy
4x Psychic Energy
3x Water Energy
Note: Their are three extra cards in that decklist, so you have to cut some cards out, your decision if you like this deck idea.