Reborn as a Space Mercenary: I Woke Up Piloting the Strongest Starship! (Light Novel) Vol. 6 by Ryuto
With the mechanic twins aboard, Hiro and crew accept a transport job that takes them to a new star system where they run right into a skirmish between Empire ships and the hostile crystal lifeforms. Hiro charges in to save the day, but gets more than he bargained for when he draws the attention of military VIPs. Worse yet, Lieutenant Commander Serena now has a new request: a deadly raid on a galaxy swarming with battleship-sized crystal lifeforms!