Basically, when you do the arena you go up against unnamed characters that will not count as "murder" but as the champion, who I can't remember the name of, has a name and it counts. This is really good for people who are struggling for someone to kill that wont restrict a quest from them. Also the fight is normally tough and difficult but if you complete the miscellaneous quest "Origin of the Grey Prince", the champion loses the will to live and asks you to end his life in the arena. When you go up against him it appears hes going to fight back as he rushes at you but then stops suddenly and begs you to end his life. I had a play with him here but just kill him all the same. Behold those long wanted word in the top corner, "Your Killing has been observed by force unknown", or something like that.