This is the character design book by Hyung-Tae Kim.

It contains characters from Magnacarta, Magnacarta the phantom of avalanche, The War of Genesis III Part.2, The War of Genesis III. At the back of the book are a few pages of line sketches.

The character designs are marvelous.

Included as a bonus is a how-to-paint process, although there are no captions.

Here are direct links to the book:
Amazon Japan |YesAsia USA

If you buy from the links, I get a little commission that helps me get more books to feature.

Here's the Amazon Japan buying guide for your reference.