Azelf is a small, gray-blue, fairy-like Pokémon. It has two tails that each have a red jewel on them. Azelf has a partially cyan face with another red gem encrusted into its forehead. Azelf has a cone-shaped head with elf ear-like protrusions on each side.

Along with and , Azelf is a member of the lake guardians, a Legendary trio first discovered in the Sinnoh region.

Azelf's spirit can leave its body without dying and can return to the body at will. It sleeps at the bottom of a lake to preserve the balance of the world. It can control an individual's will or enter the body of an individual. Legends say that if Azelf is harmed, it can cause humans to lose all will inside of them, making them completely immobile for all eternity. Azelf is highly feared due it having the power to manipulate the will of foes into its own puppets. It was shown in The Needs of the Three! (DP151) and The Battle Finale of Legend! (DP152) that it can teleport itself, as well as other Pokémon and humans. Azelf can be very cautious around people and Pokémon. However, if threatened, it will reveal its bold side. In the past, it has been referred to as the "Being of Willpower" due to its role in giving humans the determination to face challenges in life. Alongside the other lake guardians, Mesprit is needed for the creation of a Red Chain. Either through gems extracted from its body or through its fang. Together they're also capable of destroying a Red Chain. They even have the power to calm down and should the deities be enraged, but not both at once. In Pokémon Legends: Arceus, Azelf is shown to be capable of speaking the human language via telepathy.

(Source: Bulbapedia)