Theobroma, or Criollo, is a brown- colored sweet. It opens the mind to magical influences by relaxing the mental defenses. Magicians in Sitia use to as a training tool where a fledgling magician is close the subject.
It was used on the Commander to break down his mental defenses. Using it in this manner is considered to be the same as rape.
The only way to break the control is to kill the person using it.
Both Theobroma and Criollo are related to chocolate. The cacao bean (used to make chocolate) is actually the dried and fermented version of the tropical tree Theobroma Cacao, while Criollo is one of three major subdivisions of cacao.