Hi, my oponent was with 6 prizes but he do naganadel GX attack so he went from 6 to 3 prizes, then when i used my marshadow to copy my trash pkmn (pheromosa gx attack) to hit dawn wings necro was blocked(doing the block animation)
That's the answer then. He had not taken any prize cards, so DW took 50 x 0 = 0 damage.
Until recently, there hasn't been much (has there been anything at all, ever?) that would change the number of prizes a player has without the player actually taking prizes, but in the newest sets we have multiple cards that do just that.
"Swishonk!" That's what's happening!