You Sent Me to Fight Invaders. I Went Nuclear.

A modern special forces soldier dies and wakes as the useless third prince of an ancient dynasty, framed on day one by his brother and a scheming woman. Just as foreign invaders arrive with firearms and threaten the kingdom, he unlocks a modern military arsenal. Tanks, aircraft, carriers, and weapons no one in this era can understand become his answer to humiliation and war. They told him to resist the invaders. They never expected him to erase them from the map.