I have been running Legacy strikes like a mad man over the past several days to try and get Cytherean Bloom and Refraction Melt to complete my shader collection. I believe these and other shaders have been bugged since a past update to where they no longer drop if you didn't get them in Year 1, possibly to the extent that you can only get ones you have already gotten. Given my plethora of striking in the past week, I feel I should have gotten either one by now. Also, their Armory page says they can drop from Prison of Elders and Strike playlists, while the shader kiosk lists them as "Crucible and Strike" playlists. Any help is appreciated!