If Pidgeot EX uses Mirror Attack after being attacked by Lucario GX (30 damage - 20 resistance for 10 final damage) what would the return damage be, 10 or 30?
The description says if this Pokemon is attacked last turn, it will do the same amount of damage back. 30-20=10, so lucario would do 10 and pidgeot would return for 10 damage. It doesn't copy the opponents attack, it does the same amount of damage dealt to it back. Source: https://www.pokemon.com/us/pokemon-tcg/pokemon-cards/xy-series/xy12/64/