I can't seem to find much information about Valentin, except that he is German, and that most people posting about him online seem to think he's a woman. What I can tell though, is that he's one of a select group of illustrators nowadays who are able to make digital work that is as emotionally compelling and beautiful as traditional painting. I love the soft skin and glowing backgrounds, and the hints of geometry and symbolism in his work. He says he is influenced by James Jean and Sam Weber, and I can definitely see the connection in his work. His name also sounds like Valentine Fisher, which is pretty cool as well. Here's his website and blog.