The heroic character thing has my man interested in returning to the game. He wants to play an assassin and I'd like to know what the most complimentary class I could play. He'd like to get through to higher content that he hasn't seen yet and maybe do some light raiding. I don't really care, I just want to be able to play with him again and do what I can to keep him in game. What class should I roll up?
My wife and I did this combo for a very long time. She had a Mystic. worked well. However, I bet a Defiler, Inquisitor, or Fury would be even better because an assassin is single target dps, and the Defiler, Fury and Inquisitor offers aoes for when you are getting large groups.
I've played this combo with an assassin friend as a Warden. It's a pretty good combination. Assassin and Defiler, though, is pure Evil.
I keep seeing healers mentioned, but no tanks. I would think a tank would help an assassin make better use of their rear/flanking attacks.