Essex is a talented biotic and a member of Delta Squad, a special forces unit of the Alliance deployed to Fehl Prime in 2185. He has a very carefree and easygoing nature, added to his ever present air of overconfidence. Being ostentatious, he is constantly bragging about his biotic abilities. However, he is a very gifted biotic and takes enormous pleasure in defeating his enemies, being quite casual about it. He is attracted to a fellow marine Kamille, who however rebuffs him whenever he tries to approach her. Even in a near-death situation, he is quite cool and utters his favorite statement "Just trying to look cool before I die".