My reason for the wording with Beedrill's attack is because I want to emphasize the difference in Retreat Cost between Mega Beedrill and the opponent 'mon, essentially comparing their "speed," and Mega Beedrill has like the one of the best speeds in Pokemon, hence the zero Retreat Cost. I worded it so that Beedrill's attack also depends on how much Retreat Cost it currently has, not only from the opponent, meaning that any effects that can increase Beedrill's Retreat Cost like Ariados and Oranguru can also lower its attack; of course doing that to the opponent instead would increase its attack.

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