Are there any Pokemon in the current series that have moves like Mewtwo Ex's X-Ball? I keep crushing my gf's deck with Mewtwo's X-Ball and she is getting very angry and wanted me to ask. I googled it but couldn't find an answer. Thank you!
Mewtwo-EX is the only Pokemon that has an attack which deals 20 damage per energy and also attached to the defending Pokemon. Mewtwo-EX is countered by itself, so you should probably get some Mewtwo-EX tins for your girlfriend !
You wait for your opponent to commit energy to their Mewtwo-EX and then you use your Mewtwo-EX with a Double Colorless Energy and an energy switch to KO their Mewtwo-EX !
Alternative counters to Mewtwo-EX are Sigilyph from Dark Explorers which has the "Safe Guard" ability which prevents it from being damaged by EX Pokemon.
Darkrai-EX can 2 hit KO the Pokemon and has resistance to Mewtwo-EX so he can be a viable attacker against it.