Sophisticated tools known as minkisi (the plural form of the singular nkisi) are used by Yombe ritual experts to petition ancestors and spirits for assistance with a range of social and political concerns. Each power figure is the result of collaboration between a sculptor who creates the underlying form, and a specialist (nganga) who applies a variety of materials believed to have medicinal or spiritual power. In the Lang power figure, the box applied to the stomach holds the charged substances. Through this process, the complex and multilayered figure gains meaning and becomes a receptacle for a particular spirit. The diviner, healer or mediator petitions the nkisi by driving a nail into its surface. Minkisi are therefore dynamic records of their history of use.The Lang nkisi is an nduda, a small power figure often employed for divination related to warfare. These types of minkisi generally include mirrors, which are used by diviners to determine a warrior’s suitability for battle on a particular day. A headdress of quills and reeds, a fibre-filled cloth around the neck, an intricate wrapping of cloth around the waist and between the legs, a bell and a pouch are some of the other materials that help create this figure’s arresting presence.