Dude, the Shader are available and out there, you just have to play! I was able to get Arctic and Substance 321 Shaders by leveling up Cryptarch 4 levels yesterday, maybe i am just extremely lucky! I was also able to get God of War shader by leveling the crytarch 3 times in the same day...see the pattern! Try leveling him up several time in one day and see what happens.