Zero no Tsukaima: Final 1x6

Worried that the princess may be blamed for Fouquet's theft, Louise volunteers to go out and catch her. With Kirche, Tabitha, and Saito tagging along, they travel to the last sighting of Fouquet with Longueville. There, they discover the hiding place of the Staff of Destruction only to have Fouquet's golem appear. Wishing to show her worth, Louise tries to take it head on with a spell, nearly being crushed in the process. Only by Saito's quick reflexes is she saved. Her confidence broken, Louise breaks into tears. Saito is moved by this and begins attacking the golem in her name. After discarding Kirche's sword and drawing Derflinger, the runes on his hands glow once again and his ability greatly increases. Louise tries to help by taking out the Staff of Destruction, which turns out to be a "M72 Light Anti-tank Weapon system(LAWs)" rocket launcher from Vietnam War. Immediately recognizing it, Saito grabs it and quickly uses it, blowing up the golem.