Broken Hero by Xavier L Hernandez

Luis Hernandez is a teenage kid that attends school at Cardinal High. One day, Cardinal High gets attacked by some mystery people that results in the death of Luis's best friend. Holding his friend's lifeless corpse in his arms pushes him on the path of revenge. Luis becomes a hero after saving his school and continues to get hunted down. After being hunted, Luis starts to search for answers about why he was highly trained in fighting and hacking. His search for answers leads him to find out about his superhuman gifts and a secret war that has been going on between superhumans and dark monsters from the corners of the earth.