How Many Feathers for Master Amethyst and Above?
I just got the first few of my birds to the Master Azure card level, and I noticed that the number of feathers required for the next level was 5000. That is a large increase from the number of feathers required for previous card levels, over 1000. For previous card levels, it only took 200 or 300 more feathers each time to increase to the next level. So, it got me wondering, just how many feathers does it take to get to Master Amethyst and any other level(s) higher that there may be?