Mod upscaling Ardyn's texture to 4k like every other main character's, as well as fixing the texture aspect ratio so that they're no longer terribly stretched. See comparisons between the size and proportions of the vanilla and upscaled textures in the images tab.
The textures are an AI upscale followed by manual clean-up and fixes.
At last, Ardyn will no longer look like he's from a different game with pixels the size of a fist.