The Archdragon's Throne: Storm of Chaos

Varim's world is upended when a simple mission to suppress a rebellious nation on the southern border of the Empire turns into a bloodbath. Invaders from Earth bearing lethal weapons decimate his army, and he finds himself captured by his enemies. With the help of the mysterious and alluring half Li'Fae Amarei, Varim must fight to avenge his family and take back the Empire from a wicked usurper who has opened a gateway between worlds and has deceived the United States military into doing his bidding.