Fetishes were protective figures used by individuals, families, or whole communities to destroy or weaken evil spirits, prevent or cure illnesses, repel bad deeds, solemnize contracts or oath-taking, and decide arguments. A diviner or holy person would activate the statue, using magical substances. Fetishes gained power and were effective because people believed in them.
The nkondi are the most powerful of the nkisi. They were used to identify and "hammer out agreements"…with clear implications as to what would happen to people who broke the ahunt down unknown wrongdoers such as thieves, and people who were believed to cause sickness or death by occult means. They were also used to punish people who swore false oaths and villages which broke treaties. To inspire the nkondi to action, it was both invoked and provoked. Invocations, in bloodthirsty language, encouraged it to punish the guilty party. It would also be provoked by having gunpowder exploded in front of it, and having nails hammered into it. They were also used to literally ”hammer out agreements”…with clear implications as to what would happen to people who broke the agreements.