I'm certainly interested in Toxapex GX, heavy poisoning worked pretty well for me with M-Beedrill EX, and its GX attack is one of the best even though it may be countered by Pokémon Ranger. Toxapex GX may find its regular version to be a very useful partner. 10 damage counters between turns is lethal however if the opponent can't switch with the use of a trainer card the new pokémon will be poisoned and regular Toxapex can hit for a solid 100 damage. Energy cost is a clear issue, but I'll think of something. Rayquaza promo is worth considering.