Shards of Earth: the Final Architecture Book 1

Eighty years ago, Earth was destroyed by an alien 'Architect'. Some escaped, but millions more died. So to protect its colonies, humanity shaped the minds of Idris and others into weapons and sent them into battle. But the Architects disappeared, and heroes like Idris were forgotten. However, he's glad of it. This particular living weapon would rather retire to a shabby salvage vessel then be anyone's ammunition. Then this small ship makes a huge discovery.