Vader-- 17, 38
I’ll give you two on this one. (I have… a lot of opinions, since by the end of his life Vader has much more scar tissue than he does intact, unaffected skin.)
A. Because scar tissue is stiffer and less flexible than undamaged skin, it can seriously restrict range of motion. To ensure that he could breathe (as best he could, anyway) without the scars restricting his lungs, Vader needed extensive surgery to release the contractures affecting his chest. I don’t know a ton about surgical burn treatment, but from what little I do know I think this probably involved use of a procedure called a Z-plasty (there is a small, minimally graphic photo demonstrating the procedure about 2/3rds down this page, FYI). This would leave him with these obvious zig-zag markings up his sides, disrupting the older, waxy-looking burn scars.
B. Even more troublesome than the external scars are the internal ones. As a result of repeated injuries and surgeries (to address wounds or make life support-related modifications, etc), Vader developed adhesions, which are basically internal bands of scar tissue that link things that shouldn’t be linked. The damage from these internal structures, and attempts to fix them, resulted in the removal of some of his guts. (IE, this is how I explain Vader’s digestive system without defaulting to “well he definitely just has a space colonoscopy bag.” They just mangled him so badly that they had to take out some or all of his lower GI tract.) Because of this, I don’t think that Vader can eat solid food; he can probably drink some fluids, but may find it uncomfortable.
Once Vader learns his true destiny, he isn’t… attached to things, anymore, or people. The only thing that he can have and keep is his master and his purpose. Wanting anything else is unavoidable, perhaps, but futile— and between his work and his grief, he is too exhausted for futile tasks.
Even as this is the case, though, he can’t give up the sympathy he has for his clone troopers. His men are loyal, and they know their purpose as well as he knows his own. He can’t free them from that destiny, but he doesn’t treat them as brutally as he does other members of the Imperial military who attract his ire.
For the headcanon prompt meme.