The Ark of Knights - S1.E12

Hyaweh and Priecia face off in the graduation duel to determine the student representative. Priecia wins and decides to confess everything to Hyaweh during the graduation ball. Priecia reveals that she is the container for the true princess, and Hyaweh decides to become her knight. When angels attack the castle, Hyaweh and Priecia unleash the true power of the Ala-Gladius and become a giant glowing angel that defeats the army.