It is weak against the first two gyms as well as the sixth, and the fifth will resist it
Although Pokmons satisfying loop of sending out Pokmon, evolving them and executing their most powerful moves has remained basically the same, later sets have introduced awesome additions like tag teams, which include two Pokmon on a single card so you can see how Pikachu and Zarude would fare against Eevee and Corviknight
Heck, Wizards might release a new set by the time such a list were published
In fact, one of the reasons this was hyped at first is because of one claim: Mewtwo EX cant attack when you have Espeon in play
Its an instant, exiles instead of destroys, and costs only one mana
While other TCGs had cards in abundance, the Pokemon TCG sections were barren