I recently got my last S Rank on Hard mode that I needed (here's a link to that video: • Dragon Ball FighterZ -... ), and it was this strategy that won it for me. It's pretty easy, just try to do this every round: summon Shenron and end the fight with a super attack. If you do both of those things you'll get lots of points! Keep in mind that you also get points based on the amount of health and time that you end the round with, so try to avoid damage while you gather the Dragon Balls quickly. If you don't know how to summon Shenron, just keep hitting the Square button (on the PS4) until the combo is finished and you'll get 1 Dragon Ball. It's that easy! Continue this until you've gathered all 7 Dragon Balls, and the next time you execute the Square combo (you must have 7 bars of energy too) Shenron will be summoned! Then, just pick a wish and end the fight with a super attack. Good luck!