Since I only ever get 3* heroes with saving up diamants, I started using my diamants on speeding up the chests which you fill with monsters and heroes, so I have more chances on getting the purple elemental chests. Sometimes I am unable to speed them up, there is a wait time. Problem is that I am unsure of the logic in the wait times. Is it because you may only speed things up so many times in a certain period or is the amount of time you speed up a factor here? Does anyone know?
I hope I used the correct game terms, I have the game language set to Dutch.