Not bad, however your oppenent does have the option to play any ablity card before the actual battle. They could also miss when rolling so they don't battle at all once you've played your card. Of course, this DOES give you a chance to win a gate without fighting, but unless you combo this with a card that "forces" battle, then you might not even get to fight regardless.
Err...no.In order to play that ability card it would have to be YOUR turn, not the opponents. It says "before you roll a Pyrus bakugan" and the effect takes place in "any battle this turn". Meaning You have to initiate the battle that turn. An opponents bakugan has to already be standing on the card, thus no interference by the opponent. the problem you have to worry about is rather yourself missingAn opponent would have a difficult time playing an ability card before the battle....Ability cards always say to play during a battle, after a battle, after YOU roll, before YOU roll, or after an opponent rolls. During and after a battle is not before the battle, an opponent can't roll a Bakugan if it is not their turn ( and it has to be your turn if your going to play that Pyrus card), so the only playable ones are "after an opponent rolls".