"But no Esu, either! How that would irritate...her...if she even...still rages..."— Bul-Kathos(src)
Esu was drawn to the power and ferocity of the elements, and gained mastery over the powers of storm, earth, fire, and water through intense meditation.
Bul-Kathos regarded Esu as being somewhat prideful, that it would have irritated to her to know that she had been forgotten by humanity. He also had a dim view on her use of magic, stating that the Worldstone was sealed away "from those like Esu," who would have used its power to ravage Sanctuary.
- The month of Esunar is possibly named after her.