Esu is the messenger of the oracle, taking sacrifices to him and bringing his commands to men, acting under his orders and punishing the wicked for him. In a battle with Death he lost his club, but Orunmila recovered it for him and that created a pact between these two divinities. But Esu is also important in his own right, and he is greatly feared for the evil that he can do. He sometimes impels men to evildoing. In this character, he is Elegbara or Shigidi, the avenger. Esu is also looked upon as protective and even benevolent: he is called “father.” He is said to have two hundred names, which indicates that he is a many-sided, diverse character. Esu is an orisa (a god or spirit), so instead of four hundred supernatural powers, the Yoruba often speak of four hundred and one, Esu being the divinity on top of the four hundred. He is regarded as one of the most powerful orisa, capable of changing his form at will. Each odu (an odu is a chapter of Ifa, an immense volume of traditions, consisting of 256 chapters, or odu; each odu contains from six hundred to eight hundred poems known as Ese Ifa, totaling as many as 204, 800 poems) is governed by its own Esu. There are 256 different forms of existence that Esu can assume. But Esu is also a kinsman of the Ajogun, malevolent supernatural powers; the eight Ajogun warlords are his errand boys. Esu is like an impartial judge who mediates between the benevolent and malevolent supernatural powers. He is able to do this by using a sacrifice provided by a would-be victim. When Esu presents the sacrifice to a warring Ajogun, the Ajogun allows his victim to go away unhurt. But if a would-be victim does not perform sacrifice, Esu is not in a position to help him.
Esu the divine trickster tricked the High God, who then lived on the earth. God became so angry because of Esu's trick that he withdrew from the earth and moved to heaven. Esu was to bring him regular reports from the earth, and so it is that Esu became the messenger between heaven and earth. See also: Fa, Ifa, Legba.