Aello (アエロー, Aero) is a recurring demon in the Shin Megami Tensei series. She is the sister of Kelaino and Ocypete, and is the eldest of the three sisters. Aello is associated with great speed and her name literally means "storm swift".
The eldest of the three sisters ruling the Three Harpy Sisters, and the daughter of the sea god Thaumas and Electra the Oceanid. Her name means "storm" or "gale". She has the head of a woman and the body of a bird. As queens, Aello and her sisters are blessed with beautiful faces and graceful limbs, and give off a fragrant aroma.
The Harpies live in the sacred Dikti Mountains of Crete. They are considered goddesses of death, and at the same time goddesses of rainbows. They are believed to be divine manifestations of the wind. -quoted from the Demonic Compendium from Shin Megami Tensei IMAGINE
Shin Megami Tensei IMAGINE
Aello can be found in the Shibuya Quartz dungeon and in the southern parts of Shibuya. She can be fused by combining an Elf Fairy and a Bicorn Wilder. Aello reflects slash attacks and she is a primarily a speed based demon, focusing on ranged attacks. Her weaknesses include all gun styles (penetrate, spread, etc) and force attacks.