After everyone else has either run away or died, what's left of the chariot crew hiding in the woods is just Mora and Valan. Mora's the one whose job it is to stay alive after everyone else, to destroy everything the Azanis might want as spoils.
Valan promises it'll be okay, assures Mora he can do what he has to, draws his knife - all the while he's moving closer. They're not enemies - not to Mora's knowledge. There's no reason for him to run from a friend coming toward him with a knife.
Valan finds himself badly positioned to cut Mora's throat, stabs him in the stomach instead, leaves him there dying slowly. Azan can have everything they have left to give now.
He waits for someone to find them.