Elea

Elea is a Yiris.

Personality
All we know at the moment is that Matt described her as a stubborn person.

Appearance
Elea is pale blue with dark blue long hair and light gray eyes, like Yiris usually look like.

Story (spoiler alert)
She was taken by the Yiris around the same time Matt was taken. The two of them made friends but she eventually gave in and joined the Yiris, which damaged their friendship severely.