Arcanine EX
Arcanine EX is a powerful card, hitting for a lot of raw damage for relatively low energy cost. It also has slightly above-average HP for a second-stage Pokemon. But no, it actually doesn't.
Arcanine EX has a bit of an identity-crisis. It wants to be a fast-setup archetype like Pikachu EX or Starmie EX, but that one additional energy cost on its attack hurts its ability to come in fast and do its job ASAP. Fortunately, it has the raw power needed to wipe many early-game killer cards in a single hit, at least with a Giovanni boost, but losing 30 HP with each attack launched really hurts its longevity, which is dangerous for a card that rewards 2 points when KOed. Give Arcanine EX a try if you have it, because it definitely can dominate the mid-game and keep the opponent from fully setting up. But just be careful when you play it, and be ready to switch it out when it's damaged, only to switch it back in later for a hail-Mary, self-destruct play.