Essentially someone who can do a deep fake use some photos of Hayden right now with a little added aging and he would fit the look as in “How he would look uncooked by lava as a ghost.”
I mean, I personally don’t mind unmasked vader looking and sounding different then older hayden since if you look at burn victims after they “heal” or get transplants, they look totally different. Bacta aint going to get you back 100% after a lava bath.