Slow-Slow Beam Sword - 500 Years in the Future (OP07)

[Counter] DON!! -1 (You may return the specified number of DON!! cards from your field to your DON!! deck.): Up to 1 of your Leader or Character cards gains +2000 power during this battle. Then, rest up to 1 of your opponent's Characters.
[Trigger] Add up to 1 DON!! card from your DON!! deck and set it as active.