I have mixed feelings about this Epilogue.
Going from the high-end action scenes filled with intricate mystery in-between to a philosophical breakdown on existence and the meaning of the human body, it's quite the transition. The movies have the perfect balance of meaningful talk and action while this is 30 minutes of philosophy. Do you care where a personality lies within a human? Are you interested in what it means to be human? How about what a human consists of? This Epilogue presents it's own view on existence through the embodiment of nothingness that is Shiki. Once again, there is some information you learn in regards to Shiki and her personality. Again, this does bring Garden of Sinners to a closure, sort of. The anime answers questions on how Shiki and SHIKI, complete opposite personalities, and how they managed to co-exists. It just might put you to sleep. Though I liked the information but I kept looking to see when it was going to end.
The animation is superb like the movies. There are some great visuals of snow falling and even some shots that would make badass backgrounds. Lots of snow though.
Sound? Besides OP/ED....none. Besides the gentle voice of Shiki and the falling snow.
You learn more about Shiki through extreme one-sided conversation. Read above for clarification. What is destined for Shiki and her bodies origin? Bear the 30 minutes and learn a lil!
Overall I would watch it, since it provides answers to questions I didn't even think to question. If the main reason you are watching this epilogue is for concrete evidence about Shiki and Kakuto, then yes, they remain with each other. It's a different approach than the movies were but it goes by quick and in the end, learning about Shiki is worth it.