I have a theory to be tried out (unfortunately all my followers are on missions for the next 7 hrs.)
Take Koltira as your follower. Win duels (maybe 10?) in Acherus via the Ebon Knights. We have a few unique NPC's (namely Matthew Veiss) that may not like this. Maybe after our unholy duo slaughters them enough times the unique NPCs step up to challenge us...
Side note: I've won approx. 25 duels per spec without a follower/bodyguard.