If we already maxed level all the pets (for example) we cannot gain br from pets in leveling and not making it more stronger.So i suggest a rebirth pet system,when the pet reaches its maxed level it needs a rebirth pill and that rebirth pill can be bought in the shop for 499 diamonds and if the pet is being rebirth the stats that the pet has when it was still level 1 it's stats will be x2 and so the level will be x2 example if the max level of the pet is 25 so if you use the rebirth pill your pet's max level will be 50.And the pet star needed for upgrading also being x2 and also the breakthrough jewel to x2 so that players will not be stucked or bored if they already max level everything.... And to get stronger of course...