A Guy Who Reincarnated as a Fantasy Knockout and a Weapon for the Final Battle (E11)

Schwartz's great efforts have led to the devastation of the rebel army. Kalm, one of the Demon Lord army's top officers, has been guiding things from shadows. In order to keep her operation moving, she uses Ygraine and Tachibana to activate an ancient weapon called Mehpon. Even as they falter in the face of the weapon's overwhelming power, Jinguuji and Schwartz set out to subdue it. Then Tachibana, who is being manipulated by the Demon Lord's forces, uses Mehpon to attack them... (Crunchyroll)