Alright so i have gotten a total of 20 skyshards. I have the mount for myself and i sold it to someone. Now im trying to farm a 3rd set to sell again but i havnt been able to get my 21st skyshard. Now i know people will say im having bad rng, but i don't think that's the case. during the first 2 sets i was getting a shard every 800-1.2k kills. after i killed alani for the second time i am currently 6k kills into farming and havnt seen a single shard. with a drop rate of .15% i should have seen at least 4 of them already. My only conclusion is that blizzard set a limit to 20 skyshards per toon.