Courier concept/soldier

Rock d character gun

This guy used to be a courier.When the war broke out, he boldly added to the folk organization to fight against enemies.
But he hates wars,wars brings deaths!disease!and of course, he lost his families because of the war!So he has a strong belief to retake the control of his home,his life!
When he was a courier,the mechanical arm from his back could help him take huge things,and now they can help him fight against enemies!
Before he became a courier, he used to be a soldier.So he has a very good understanding of weapon and fighting skills,in this case,he could make him become the "nightmare" to enemies!!