An Adjunct was an officer selected to stand in for, and represent, any High Fist or sufficiently ranked commander in the Malazan Imperial hierarchy.
Empress Laseen employed a single Adjunct at a time as her personal servant and an extension of her will. The Adjunct to the Empress had the authority to speak with the voice of the Empress, overriding the chain of command. She was also considered a special weapon against sorcery, wielding a sword made of Otataral as a symbol of her office.
The role of an Adjunct was never intended to be one which would command armies, but they could be assigned to do so in times of necessity.