The Long Road to Karn — G. Akella

When driven by a goal, the impossible oft becomes doable, like slaughtering an entire coven of the Twice Cursed God's adepts without mercy, or leading a legion of demons to storm the last bastion of the Cursed Princedom. 

But as the impossible hurdles keep on coming, even that drive may not be enough for Krian to escape Demon Grounds, make it to the higher plane, reunite with his sister and friend, and exact vengeance on his mortal enemy....