There is a rule for screenwriting. ?Start the story as late as possible and finish as soon as possible. ?That prevent boredom and focus the story. ?In reality, we probably don't care about his childhood, that can be a three minute montage (I wouldn't do that either). ?Plus people are born a gender not a profession.
So try this (start late - end soon).
A Noble warrior must choose a side in a global conflict know his decision will bring and end to the opposing race.
A noble warrior must choose a side in a global conflict know his decision will bring about his own death.
Having a logline which is just a decision isn't really enough to support an entire film. ?Give him a goal that will have numerous obstacles.
A noble warrior discovers a secret that leads him to betray his army by supporting a greatly outnumbered local resistance, he must now rescue his family who believe him to be a traitor.
Not your story and the line needs work and tightening. ?But you can see so much conflict to explore.