Black Powder: Anglo-Zulu War - Unmarried Zulu ImpiUsuthu! The feared Zulu warcry of 'Kill!' shouted by hundreds of brave, fierce warriors would put fear into the hearts of most men. The men shouting this battle cry have a lot to prove as they are the unmarried warriors of the Zulu impis. Zulu tradition held that until they 'washed their spears' in the blood of an enemy of the King they could not choose a girl to marry, so closing and killing an enemy ensured a bride and a greatly enhanced status.