Ma'jhad Kha is a Khajiit member of the Ember-Eye Slavers. He leads the forces that took over Steelheart Moorings. He was once a slave himself, but killed his masters and competitors, taking over as a slaver king.
Slavers are using Steelheart Moorings as their base of operations and they're holding some sailors who they recently captured. The first mate has asked the Vestige to help free the sailors from the slavers' clutches.