As far as impact of this set. I feel like Evosoda isnt a huge thing. Its only okay imo. As long as stuff like Level, Ultra Ball or something like that exists. Those will always be better. Evosoda is just so specific that i feel like its just a bad card.
Things that did make an impact are stuff like Muscle Band and Yevltal. Some minor things like Trevenant, Fairies, and Rainbow Energy are also have an impact on the Meta. Though not as much as the first 2.
Yevltal is so broken. That one card has changed dark so much. They went from being heavily focused on defense without any huge attackers. But now with Yevltal Ex, they can drop stuff like Sableye and go all out offensive. It's first attack always does like 60 damage at the very least for 2 energy.
Muscle band changes things so much. 20 more damage for any pokemon is huge. Plasma might be a huge threat again with that card. Slap that on Lugia and you have potential to 1HKO most Exs with it and Deoxys. With thundurus hitting for 50 without Deoxys is also pretty crazy, it will probably be hitting 80 damage with its first attack for only 1 energy while charging your bench. Also with Yevltal being weak to Electric, Thundurus will be more heavily played to counter it. 160 (3 deoxys and 1 muscle band) for 1 energy is pretty crazy. Especially since Yevtal's damage depends on the defending pokemons energy. It also gives them reason to play 4 Deoxys to attempt OHKOs.