Originally Posted by Sinon View Post
if i understood it, you mean that people make a private room (or a room for only 2 players) and kill each other for complete the challenge. If that's what you mean, i think the solution can be make the private rooms and rooms that have less than 6 maximun players (in Duel 4 players) do not count for the challenge.
Still a big nope, I think it should only work per IP or per login account (not per character).
This would make swapping a lot harder to get the reward (and also make the challenge harder to have unique kills).