Shaymin EX was probably the least wanted EX at the prereleases next to Kyurem, and it was usually only above said dragon due to its AWESOME ARTWORK (see the full art version, too). As many have stated before, it's a downright terrible opener, as giving up two prizes at the beginning of the game will make the rest of the game a living hell in just trying to catch up, let alone claim the lead. Fire weakness doesn't help its cause, but a fighting resistance will against Donphan Prime (avoids a 2HKO), further aided by Evolite since, like all current EXs, it IS a basic pokemon. Of course, all these attribute, positive and negative, won't mean a thing unless it has the attacks necessary to be considered worthy enough to play.
Synthesis, it's first attack for (G), is really only useful for grass decks. Unfortunately, lets face it, said decks are very few, if even present. Virizion's attacks are too cheap to require the acceleration, and currently, we have Tangela to pride the exact kind of energy acceleration via attack as well.
The golden apple that will appeal to many players is its last attack, Revenge Blast starts with a baseline of a mere 30 damage for (G)(C), but that damage output gets further boosted by an additional 30 damage for each prize your opponent has taken. This generally means that its damage output will be capped at 180 damage (5 prizes taken at 150, plus the base 30 damage for 180 total). This makes Shaymin EX an excellent late game closer, but a dead-draw otherwise. However, there IS a way to up this number in a speciallized way. Some people have been tossing around the idea of adding prizes via Palkia & Dialga LEGEND's Time Control attack, while using Electrode Prime to power up said attack. Remember, Shaymin EX's Revenge Blast does an extra 30 damage for each prize card TAKEN! NOT how many prizes are left. Whether such an idea will work in a competitive format remains to be seen (I'm not set on it, myself, but it sounds fun regardless).
Modified: 3/5 Flaility is its problem here. 110 HP doesn't stand up to much of the format's heavy hitters, and that can very well be its downfall. Were it not an EX pokemon, however, things might be different, as it wouldn't suffer from the 2-prize rule. It does, however, still have late-game potential, and shouldn't be disregarded as a possibility.
Limited: 2/5 This is where the limit of 4 prizes in the game really sucks. This caps out its damage at 120 damage, which is short of KOing the regular Zekroms and Reshirams, let alone the many EXs out there. You might be better off keeping it in your binder and preserve its condition rather than run it.
