It bugged me to no end that when "Yda" removes her mask at the end of Heavensward, her entire face shape changes. While it's possible to argue that Papalymo's magic also glamoured her face to make her resemble her sister, it still bugged me.
So I made this mod! I ported her Stormblood face mesh back to her ARR/HW face, and linked the two via material editing. This means any texture upscales you have applied to Lyse's Stormblood face will still work in pre-StB content.