that night, the king of the moon appeared and a fierce battle ensued. elle and gau's attacks were devastating, even so far as splitting the demon-beast in half, but as the fight was occurring beneath a full moon, the demon-beast was able to heal even the most debilitating wounds as soon as they occurred, even regenerate severed limbs. it was kyuo's efforts in the end that saved them, her traps pinning the demon-beast in place until the sun rose, and the king of the moon's powers waned to the point where it could be, and was, killed. with her revenge now complete, kyuo had nowhere left to go, so elle invited her to join the group. she has been with them ever since.