In Episode 5, Seras and Touka face the Skeleton King as the final boss in the ruins, who is far stronger than the previous monsters.

Seras reveals to Touka her secret power, which enhances her physical abilities and creates unique weapons, and asks him to keep it to himself. However, she warns him that she might not be able to protect him if the monster exceeds their expectations. Yet, Touka uses his paralysis and poison spells to defeat the Skeleton King.

After the battle, Touka also finds a monster egg that Piggymaru wants to take. Back on the surface, Touka tells Seras that he values her combat skills and wants to hire her as his bodyguard. Seras reveals that she is on the run and conceals her true identity through the power of spirits. Touka assures her that he won’t betray her and entrusts her with his real name: Touka Mimori.

They decide to travel together to the land of the golden-eyed monsters, where Touka hopes to find the Witch of Taboos. In a symbolic gesture, Touka gifts Seras a valuable blue dragon gem as payment for her services.

Meanwhile, Seras is forced to flee when the black dragon knights attack her. In a dramatic moment, Touka saves her with his powers and renews their agreement.