He is the absolute authority in Kafira. He is the cousin to Mulili
Mulili says that Boss hides his money in foreign banks.(pg59) The logical explanation here is that the money was acquired through dubious deals.
In his guise to meet Regina so as to iron out Mosese’s release Boss tries to get Regina by force. Regina escapes by jumping through the window.
He also locks Mercedes in the palace prison when she questions him about the incident with Regina. Additionally, he gives Mulili permission to use any force necessary to silence Kabito.
He orders officials to use force in trying to stop dissents in Kafira. This results in the killing of Adika, Nina, Doga and Kabito.
Some of the people who try to oppose the regime of Boss also end up in prison eg, Mosese and Jere.
Furthermore, he rules for too long while creating pain and suffering to his subjects.