Having an ugly, despicable, grotesque kind countenance speaks more truth than a damned, twisted soul dressed in beauty....
Those words basically sum up the entire aftermath feeling I go through once I've come to the last page of Dr. Jekyll and Mr. Hyde by R.L.Stevenson. It reminds me so much of epic characters like Gollum/Smeagol, Dr. Frankenstein, Dorian Grey, and Edgar Allan Poe's characters, etc. who lived double lives to shush up their considerably selfish, twisted souls.
Most people call Hyde and Jekyll's case schizophrenia but I don't think anyone could sum up that experience to a mere biological disease. His shifts in countenance was more dug down deep towards his soul.