Alternating Current synchronizes well with this ability. It provides more attack speed and 115% of your CP as BONUS damage every other shot. Add that to the 0.7 Crystal damage per shot and make sure that Koshka is slowed, and she's dead for sure unless she gets healed or teammates ambush you to protect her. I'm no Ringo expert, but I imagine that tactic would work well finishing an Ace.
I didn't quite get that yet. Thx for help!!