Did you do all the illustrations for your book? And, if you don't mind, what part of the art process were you involved in whilst creating Diablo2/3? Character design, weapons, armor, environment, doodads, a little of everything?
I'm working on illustration now in hopes of doing concept art in games is why I ask.
I encourage you, all the way. You have to just go for it hardcore.
My work on D2/D2X/D3: Oh man, it's a blur these days, but I did tons of little things. I started at B.N. working on cinematics, making a montage with a burning cathedral - then we consolidated the cinematics down at Blizz South. They had tons more experience at it, that was a relief.
After that, I put the first ground tiles together, creating the base tiles for Act 1, 2, 3, and eventually 5. I made ground, paths, grass, trees, bushes, rivers, rocks, desert, temples, big stone heads, docks, boats, jungle, swamp, tundra, cliffs, mesas, ice cliffs, ice caves, omg... I lose track. I also made lots of little things, like various barriers, coffins, altars, and stuff. I was often asked to add "grit" to indoor scenes, by painting blood and dirt and wear and tear. When art looked too clean, I was asked to "Boosify" it.
I also made the angel and demon UI, and most of the UI ornament and scrollwork... Lets see... the inventory screen, the quest log, stash, tons of icons and buttons... on and on. I'm pretty proud of the battlenet UI - especially the clickable gem
Also some box art and manual illustration (the Diablo BattleChest art). I painted some weapons, scrolls, potions, gems, doo-dads and lots of little crap too. I can hardly remember, but lots of little stuff all over the place.
For D3, i was utterly burned out on environment stuff, so i worked on prototype UI and lots of monster and weapon concept stuff. But I'm really not sure what will make it into the final game, given the technical and team changes. All in all, I played my humble little role, adding a certain look to the Diablo world. It was a team effort, and a huge challenge, because all the work was so limited in resolution and often had to tile together in little squares. Argh!
As for my book, I'm the author and illustrator. I sit here monk-like, and just do my thing to the sound of blaring music.