In ancient Nehekhara, Nekaph would stand in Settra’s place should anyone be foolish enough to challenge the king to single combat or call his honour into question.
Nekaph must always issue and accept challenges (if possible). However, challenges issued by Nekaph cannot be refused. In addition, whilst engaged in a challenge, Nekaph strikes a Killing Blow if he rolls a natural 5 or 6 when making a roll To Wound, rather than the usual 6.