>>5947>Since Kuroba's RPB is her trump card, I'm assuming she went for her secret technique that made her win the match (the one we haven't seen yet, alluded in >>5777 )RPB is not her trump card, it's her regular card. She uses it on opponents weak enough to have fun against, it's full of love and dokidoki.
Even her merciless and "dull" style of play, the reveal of which is being built up right now, is not her trump card as she's been using it in every match after chapter 0.
Her trump card is her "Driver of the South" playstyle that Mogami says she won't ever show (but narrative convention dictates that we WILL see it eventually, probably in the rematch after they both pass to the next stage of the competition)