Fly Greena Aight

 is the head researcher at the Astarian National Research Facility Building 8.

History
When he was young, Fly would visit Aaron Newt to borrow books and help him with his research. When he grew older, Fly officially became Aaron's research assistant. Over the years they would implant Anima into Blanca. After Aaron botched an Anima implantation experiment on himself, Fly took over as head researcher.

At some point Cooro was brought to the research facility. Fly befriended him and got Cooro to promise to one day give his Anima away.

Plot
Throughout the series, Fly is keeping informed of Cooro's whereabouts. He also talks to and teases Igneous Giesrieg about his travels.

He eventually finds Cooro, and brings him and his friends to the Astarian National Research Facility. There he unsuccessfully tries to convince Husky and Nana to give up their Animas. Cooro stays but the others leave; Fly removes Cooro's Anima and implants it into himself.

When the king and Lord Nuoref arrive to inquire about his research, Fly goes to greet them. Blanca comes out and flies away, and Fly follows her with his newly acquired wings. As he catches up to Blanca, his wings start to disappear and he falls from the sky in Blanca's arms while she too disappears.

Trivia

 * In Parallel 2, a short story written before +Anima was serialized, Fly appears under the name "Greena Eito".
 * Fly's name has been spelled inconsistently throughout the series.
 * In the official English translation, in Chapter 27 and Volume 10's blurb, Fly's name is misspelled as "Fry". It is spelled as "Fly" throughout the rest of the series.
 * The official romanization in the Japanese volume releases use "Fly" in Volume 3 but use "Fry" in Volumes 4 and 10.