Sarkhan is a planeswalker who believes that dragons should be worshipped as gods. He wandered Jund, learning about the dragons that dwell there before finding one of the most powerful dragons to ever exist - Nicol Bolas. Sarkhan pledged total obedience to Nicol Bolas, who used Sarkan as a way to keep tabs on the other planeswalkers.
Nicol Bolas sent Sarkhan to the plane of Zendikar, where he watched over the Eye of Ugin. he stayed there for many a year, slowly losing his sanity until eventually two other planeswalkers came to find the Eye.
Now the eye is open, and Sarkhan knows his master will not forgive his failure.