Flameu

Flameu is a traveler of Geosis and alchemist who became the managing elementary body of research facility Geosis (The Unexplored Ruin). Several hundred years ago, she took the form of a human and also became unaging. She is usually seen floating, and can disappear and appear as from thin air. Her existence is mostly shrouded in mystery and she rarely interacts with humans.

(Source: Atelier Wikia)