This is the eighth episode.
They are ready to attack it in order to defend her, but Hikaru tells them it's safe because it's her new friend Hikari. They don't fight it, but Hikari transforms and runs amuck in the forest, setting fires, and causing damage. Hikari also knocks Fuu unconscious, and gets a hold Umi.
Hikaru at first tries to reason with her new friend, and this works momentarily. However Ascot becomes angry and insists Hikari finish Hikaru and her friends off. Which it tires to do, though reluctantly. Despite her affection for the creature, Hikaru fights and eventually kills Hikari.
The girls bury Hikari, and experience another earthquake. So they hurry off to find the Rune God's.
- The real name of the creature Hikaru christens "Hikari" is actually Vigor.