Thanks to the praying cards in your hand, you will be able to influence the outcome of the fights, but you'll have to do it swiftly: since all of the action is happening in real time the enemies will attack you as soon as they can, whether you played your cards or not. No need to rush into the melee though, for the boosts you give to your character carry on between the fights, so take your time to wisely select the cards you will take with you on your journey.