Thorne is on the cover of the artbook. http://www.amazon.com/The-Art-Halo-5-Guardians/dp/1608876497%3FSubscriptionId%3DAKIAJJY2YKHHLJKYIBNA%26tag%3Dslk03b1-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3D1608876497
The art might have been created before Nathan Fillion committed though.
What's the difference between these two? Does anybody know?
http://www.amazon.com/Art-Halo-5-Guardians/dp/1608876497
vs.
http://www.amazon.com/Art-Halo-5-Guardians/dp/1405281839
Fall of Reach is the first piece of Halo media (Book) that came out back in 2001. You can either get the original or the 2010 or 2011 edition. I think the definitive edition just corrects certain mistakes in the 2010 version.
However, as a cool Christmas gift... I recommend an art book of the games. They're an awesome gift.
http://www.amazon.com/The-Art-Halo-5-Guardians/dp/1608876497
Halo: Evolutions: Essential Tales of the Halo Universe is also a collection of fun stories.
Original: http://i.imgur.com/W44HWG9.png
It was from a concept art in The Art of Halo 5.