Essel is a Blackguard archer and informal mentor to Teia. She is known for her bawdy sense of humour.

Essel's mother was Delilah Tae, a sub-red drafter who gave birth to her daughter when she was 22. Her father was Pollos, a red drafter. Both her parents fought in the war, apparently on the side of Gavin Guile, because their commander used their idea of shooting red luxin into the air and igniting it while airborne to terrible effect in the burning of Garriston. Pollos died under unknown circumstances before the end of the war, and Delilah undertook the Freeing immediately after the war closed since she was starting to be unable to control the sub-red. Before he Freed her, Gavin promised Delilah that he would take care of her then-three-year-old daughter, Essel. Essel was brought to the Chromeria to be raised and educated, and elected to train as a Blackguard while studying at the Chromeria's drafter school.

Numerous remarks are made about Essel's beauty and, especially, her body. She is petite but curvy, and has large breasts. Because of this, she is the Blackguard who lectures the female trainees on the history of the Amazoi, a mythical race of warrior women who cut off their right breast, or left if they were left-handed, unless their breasts were small enough to not impact their (prodigious) archery skills.

During a notorious (and, to the Blackguards, amusing,) incident, Essel was one of the Blackguards who escorted the White to a ball being thrown at the Atashian embassy. The ambassador took a liking to Essel, and made amorous advances to her. Although Essel was also attracted to him, and would have enjoyed it had she not been on duty, she considered it unprofessional to pursue romantic or sexual gratification while she was supposed to be protecting the White. While Essel was on her break, the ambassador kissed her, and although Essel enjoyed it, she broke away and told him no. The ambassador thought that she was just being coy, which Essel told him she wasn't. The ambassador then started getting aggressive and kissed her again, at which point Essel gave him an ultimatum that she would not warn him a third time. The ambassador "put his hands on [her] in a way she felt objectionable," so "I broke his fingers. Most of them." After the ambassador had been patched up, he went to the White, told a ridiculous story, and furiously demanded redress. Orea, trusting the Blackguards absolutely, did not even bother asking for Essel's side of the story, merely asking her if she had acted improperly. Essel told her she had not, and the White told the ambassador that he would be lucky if the White did not have him expelled from Big Jasper.

When this story was recanted to a group of female Blackguard trainees, Samite added that the Prism, Gavin Guile, is even harsher towards those that interfere with the Blackguards.

When the Chromeria fleet mobilizes to defend Ru, Essel is one of the Blackguards that goes with the fleet to augment the Chromeria regular forces. While on the flagship, Wanderer, Essel breaks a sailor's nose due to the sailors' incessant ogling of the female Blackguards.