Terminus (Fringe Worlds #1)

Being the sole survivor of humanity’s first bloody encounter with the alien Vacra had cost Gant Maker his military career. However, upon the Vacra’s return, Maker is reinstated and – assisted by a band of military rejects (including a blind sharpshooter, an unstable psychic, and a genetically-engineered killing machine who refuses to fight) – ordered to hunt this enemy down on a distant world. $0.99 on Kindle