I Am a Military Advisor and Have a Harem

Unexpectedly, I had accomplished nothing and actually traveled to the battlefield where humans and demons were fighting, and was captured by a beautiful knight? The first step was to start as a handyman, and then lead the army to fight against the demons. I got the favor of the goddess, and she actually made me a military advisor! Since I want to be a strategist, I must be the best strategist in the world. See how I use military tactics to gallop on the battlefield and have a harem at the same time... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.