I just want to say that this story was amazing. You managed to create such a tense atmosphere throughout and your characterisation of Voldemort is spot on. I really like Vincent's realization that he is not going to leave alive.
This story reminds me a lot of The Portrait of Dorian Gray by Oscar Wilde. It has the same self-obsessed subject as well as the idea that a portrait can capture not only the soul of the subject but the soul of the painter as well. I love the ending of this story, especially the last line.
My only criticism is that you could maybe lose the eights. It kind of looks like a row of ants marching across the page and interferes with the mood of the story.
This was very good. I'm not sure that it is entirely believable, given what we know about Voldemort and his confidence in his Horcruxes, but the idea is still very interesting. The enchanted paintings around Hogwarts and other wizarding dwellings are never really discussed in the books beyond what Harry absolutely needs to know, so I think it's cool that you explored more details about this particular branch of magic. The story was well written and I enjoyed reading it. Great job!