The highest printed base damage on a tournament legal card is 200, shared by Mesprit Lv. X and Lugia ex. However, there are a number of Pokemon that, in a given circumstance, can surpass that. For example, take Magmortar SW, who can deal 20 damage x the amount of energy equipped. If you can equip 57 energies (barring two slots for the Magmortar line, and 1 for a final prize), he can deal an astounding 1140 damage. Or if you're feeling lucky, Electivire SW can turn those 57 energies into as much as 2850 damage (or as little as 0, depending on your coin flips.).