I am attempting to make a recurring nemesis for the party, but I am stumped as to how to keep him from dying. I don't want to wipe the party with him, just put him in for a good story element. But I don't want to make cliche and overall dissapointing events occur for him to escape. He is a Free - Willed Undead Black Knight who's overall goal is to get revenge on the main villain, who raised his soul from rest to become an undead being. He wants to die, but only in a one on one duel, no holding back. anything else would be dishonorable. I want him to be a potential ally to the party, but he is slightly villainous due to the fact that the dark magic within him has made his judgement of good and evil impaired. How can I make a good reacurring nemesis (Who will later either become and ally, or die) without him dying early or getting groans from the party?