I'm really new to the whole twinking thing and I've mainly started because I'm really starting to get bored of just doing the same thing at 120. Main point that I'm wanting to know is what class has the most damage output in PvP with shadowmourne?
If you're wanting to twink with Shadowmourne it's going to have to be for PVE content, otherwise you're going to level out of the bracket where it's useful.
Ret paladins are very good against most other melee classes and most ranged classes
shadowmourne would fit better with a paladin if you are looking to twink