What is the criteria?
In my alliance top players are gifted with yin crystals which resulted in 2 star dups, whereas younger players are gifted with singularity crystals which resulted in 3 to 5 star champions.
I am still pondering whether the criterion is country or race as all the players whom I personally added in my alliance got 2 star and all who belong to foreign countries received singularity crystal.
I am hurted by discrimination.