In the course of time, make it harder to meld Mythic Ducklings

There is currently no hard cap for the number of Mythics that can be minted. In a way that is a good thing, because if there is a hard cap and that cap is reached, it is end of game and whales will take over. However, the current set-up will allow an inflation of Mythics. To early minters, such a dilution can easily grow unfair. Therefore, the proposal is to gradually make it harder to mint Mythics. This can be achieved by increasing the number of Legendaries or DUCKIES for melding.