Mawile's Jaw Bite does not specify Mawile doing the damage so say I use Jaw Bite, then on my opponents turn Mawile gets KO'd, can my new Pokemon do +20 in attacks? Similar question if I retreat Mawile on my next turn after using Jaw Bite does the new attacker get to do +20? :metal:
Since the bonus damage is "after applying Weakness and Resistance", that means the effect resides on the Pokemon being attacked. So, Any of your Pokemon that attack it next turn get the bonus damage as long as their same defending Pokemon has remained in the Active position.