Heres how to get a good Challenge Mode Super Easy run.

1. Your monsters must have 1 of each Harpie Lady.

2. Equip the Red Harpie with 3 Red Medicines.

3. Equip the Yellow Harpie with equips to buff up the Harpies.

4. Equip the Blue Harpie with 3 Monster Reborns.

5. Spam the Special (Z) each turn until 1 of the equips is needed or until you run out of Specials, especially on Kaiba your gonna need the luck, if he plays Blue-Eyes Ultimate Dragon, it's likely that you'll lose the Specials and also lose all the stars. (I got lucky and won whenever me and Kaiba ran out of stars.)

Tips

1. BE SURE TO WATCH YOUR HARPIE'S HPs IF THEY ARE LOW YOU NEED TO WAIT TIL HARPIE LADY RED'S TURN COMES IN TO USE RED MEDICINE ON THE WEAKEST HARPIE. IF YOU LOSE THE BLUE HARPIE(with Monster Reborns), YOU'RE SCREWED. IF IT'S YOUR TURN AND IF IT'S THE WRONG HARPIE, GUARD AND HOPE YOU GET THE RED OR THE BLUE HARPIE'S TURN(Whichever is needed.)

Good luck! :)