Mercenary’s War

Gao Yang was a military enthusiast, an ordinary one, who loved knives, guns, and adventure.
In an accident, Gao Yang found himself in Africa, where he unfortunately experienced a plane crash. Although he miraculously survived, his life henceforth was one where he could only scrape by under the muzzle of guns, for he had become a mercenary.
What heights could a military enthusiast reach in the international Mercenary World?
Please, wait and see.