From what I understand he is a well-known Spanish comic book artist and is publishing a book on Steem. My guess it was done to showcase and raise exposure to quality content.
You can check out the quick trailer on YouTube of the book.
Looking over his first post he seems to be pretty badass.
"I've worked on series like "CSI MIAMI Smoking Gun", written by Jeff Mariotte, "2 to the Chest", written by James Hudnall, "Monarch of Manhattan", written by Edward C. Sellner, "Worlds of Dungeons & Dragons - The Great Hunt" written by Elaine Cunningham, etc… My first lonely work was "Desde la Oscuridad", a compilation about my horror short stories published in "Cthulhu" magazine. I've also been working as inker for american publishers like DC Cómics, IDW, etc…"
I know nothing more than you other than this observation.