Senu was a masked Seguleh warrior. By his own admission, he was fourteen years old and an Eleventh Level Initiate. Like his people, he chose not to speak, instead using body language to communicate with those around him. He was described as a short, lithe man with dark eyes.
Senu and two other fellow Seguleh, Thurule and Mok, were either enchanted or coerced into the service of Lady Envy before they were introduced to Toc the Younger and Tool. Since he and his brothers were the Seguleh "Punitive army" aiming to directly challenge the Pannion Seer, he travelled with them in order to fight the Pannion Domin.