The Iron Banner

The Iron Banner is a fantasy story, that tells the life of a young boy called Bobby. After a terrible tragedy befalls his family and his village, Bobby is recruited into a mercenary company called the Iron Banner, and becomes responsible for telling the history of the sellswords as they grow from a small band of rag-tag warriors, into a fully-fledged professional fighting force, to what can only be described as a superpower for hire

This is the first book of (a planned) series of 5.