Imperfect Weapon by A B Potts
Approx. 167,710 words.
Published on November 12, 2011.
The universe contains an infinite diversity of sentient life forms. The Sallows intend to rectify this. Genocide is their business; slaughter and mass destruction their entertainment; thus they have developed their ultimate Warrior. A blend of blood and machine it looks humanoid but is driven by programming. The only problem is he is just a kid and like any kid, he's got a bit of an attitude.