The biggest things that need to happen is, make it worth doing. The droprates suck, and if you dont have a certain point score you are basically just going to be doing it for fireworks. Give us a goal to work for and not just put us at the mercy of the rng.
They also need to fix the lockouts for when you win. An efficient team will be locked out of the fight for about 50% of each battle phase because the fights are so short.
