The odds of you being able to use this attack at least twice before it is KOd is very low
Umbreon ex (112/161, 193/161, & 208/161) Stats: Stage: Stage 1 (evolves from Eevee, a Basic Pokmon) HP: 140 Energy: Darkness Attack Power: 80 Special Ability: Once per turn, Umbreon can forcibly swap an enemy Pokmon with damage on it from the bench to the active spot Retreat Cost: 2 Energy 2 Espeon ex (083/161, 190/161, & 205/161) Can Heal Once Per Turn Found in the Lugia Variant of Wisdom of Sea and Sky Espeon ex, like Umbreon ex, doesn't take a lot of investment to set up, but deals decent damage and has a special effect that's worth building a deck around
However, if your deck revolves around breaking boards, going second is much better
Again, this is likely due to Teal Masks popularity in the game amongst players, and helps show how much of a force players are becoming in card values as tournament attendance soars to ever greater heights