To start off let me say this deck is very good IMO. There are only a few things I don't like about the list.
First, as Sleeping Snorlax said, this deck doesn't need 4 Eviolites. 4 is just way over the top for a card that just gives your Pokemon Surviveability. This room should probably be used for more draw support and consistancy cards. After testing this deck with 3 and 4 Eviolites, I realized that I kept drawing them and needing to attach them to pokemon that already weren't in OHKO range of most of my opponent's pokemon. I suggest cutting this card down to only 2 because you just draw it too much even if the deck is all basics.
Second, super scoop up is a really risky card. This card is just the most annoying thing to have in a deck because missing the flip can kill you. It can also help you a lot, but the risk isn't worth taking. This card also begs you to junk arm for it which can lose you the game if you fail it. Since this card is mainly to pick up Shaymin, I;d suggest cutting it for another Shaymin and a Seeker since those cards always work and the second shaymin helps it from being prized.
Third, there are only 9 draw supporter cards in this deck. It also doesn't help that 3 of them are junipers. If you have to Juniper away one or more of your other draw supporters, you will be in a pretty big dead draw for most of the game. I personally wouldn't run Cheren in this deck. Drawing 3 cards is helpful, but it never really gets you a much better hand. Pokegears help, but they could be cut for 2 more PONTs. I would also suggest cutting the 4 Cheren for a juniper and 3 N. These will help you get a total hand refresh and almost gaurentee a junk arm or catcher.
Lastly, I would cut Pokemon Collector for some dual balls. These cards are great and can get you Pokemon anytime. It is good because it still gives you that option of a turn one draw supporter and lets you get a few basics after a shuffle supporter (depending on what you need based on your new hand). Dual Ball is also good so you can pull out Shaymin anytime during the game. This really helps and gets you out of chosing between collector and PONT.
So, in conclusion:
-2 Eviolite
-2 SSU
-2 Pokegear
-4 Cheren
-4 Pokemon Collector
+2 DCE
+1 Shaymin
+1 Seeker
+2 PONT
+1 Juniper
+3 N
+4 Dual Ball
-iisnumber12