Aeolus

"Well, you know what they say. If you don’t like his mood, wait five minutes. That expression "whichever way the wind blows"- that was based on him."

- Mellie talking about Aeolus

Aeolus is the master of the winds and wind gods who lives on the floating island of Aeolia. He is in charge of all the north, south, east, and west winds.

History
Aeolus was born as the son of a mortal king named Hippotes and an immortal nymph named Melanippe. Blessed with his mother's gift, he was charged by the gods to preside over all the winds, particularly the great four winds. Aeolus was said to live with his wife, Iphimedia, and their children, feasting on daily delicacies. When visited by the Greek hero Odysseus, he received him favorably and presented Odysseus with a bag containing winds upon his departure. This was to ensure that the wayward Ithaca reached home safely, but the curiosity of Odysseus' men caused them to be blown far off their course. When they returned to his island, Aeolus refused to help them a second time and drove them off.

The Last Olympian
Hermes told the demigods of Camp Half-Blood that Aeolus has sent his most powerful minions to guard Olympus from air strikes, forcing the Titan Army to make a joint ground and sea assault on Manhattan. This prevents evil magic spirits from launching an air attack on Olympus, which provides safety for the demigods to walk through it's streets and enter the throne area.

The Lost Hero
At the beginning of the The Quest to Free Hera, that Jason Grace, Leo Valdez, and Piper McLean take on, Annabeth Chase suggests to Jason that she'd personally ask a wind god, mentioning Aeolus.

Aeolus appears when Jason, Leo, and Piper visit his palace to deliver some rogue Storm Spirits. He seems to have gone insane from constantly filling in the weather requests, as they change whenever the gods get moody. He also wants a promotion from Zeus to become a god, not the Master of Winds which he claims is too vague a title and that the benefits are so much better. He also ordered Boreas and the other wind gods to eliminate any demigods who seek aid, out of frustration for having to round up the many storm spirits born from Typhon's second rampage, and since he can't be mad at the gods he can be mad at their offspring. This was later shown to be a manipulation by Khione and later was commanded by Gaea herself to attempt to kill the three when he was originally told by Zeus, Aphrodite and Hephaestus, to help them.

Personality
Aeolus has gone crazy after years of trying to fill out the request of all the weather needs of the gods. He is also completely self absorbed, thinks anything about the wind is related to him, including books like Gone with the Wind, Into Thin Air, and Up in the Air. His mood can change on a dime and he makes impulsive decisions that he forgets a minute later. He also seems to have a habit of firing his assistants, as Mellie had only been working for him for twelve hours, which is longer than most.

Appearance
Aeolus wears a business suit that looks like the sky. It is mostly blue, but has clouds that move along the fabric and change shape or can become rain clouds. He looks about sixty years old with white hair and a ton of makeup. He also has a smooth face, as if he had plastic-surgery. Jason describes him as looking like "a Ken doll someone had halfway melted in a microwave."

Abilities
Despite not being a god, as mentioned in The Lost Hero, Aeolus gets additional powers, including separate powers, being the master of the winds.
 * Aerokinesis: As the Master of the Winds he has absolute control over the wind.
 * Atmokinesis: He can control the various aspects of weather.

Trivia

 * Though only an immortal in the series, Aeolus is sometimes called the god of the winds in mythology.
 * Aeolus' name means "nimble" in Greek and is shared by both the legendary patriarch of the Aeolians and the mythical namesake of the Aeolian Islands.
 * Anything lost in the wind eventually goes to Aeolus.
 * Aeolus has a weather channel called "Weather Every Twelve" (shown in The Lost Hero), while Aeolus has twelve children.