Note: I posted this on the Witch Hunter forums at warhammeralliance.com as well, so if you see that, it was me, not a copy/paste. Just check the usernames if you want
Ok, so here is a fail-proof way to kill any class in open world RvR, yeah yeah, some of you may say common sense, but is it? Is it!?
So, you just ride along the main roads until you spot a lone wolf just running along, make your way towards them and just run past, if they think they can take you they'll pursue. (Just run past as if you were gonna ignore them, this weeds out people who don't have a smug arrogance that needs to be crushed.)
Let them get a hit in so that you are dismounted and then pop Flee! Your prey will probably follow since they think you'll be an easy kill that won't put up much of a fight.
Once they pop flee (believe me they will, otherwise you'll get away, in which case just rinse/repeat from the top) you immediately toss back an energy pot, preferably a 62 pt one for quick regeneration of points, and Incognito.
Hunt them down and get not only an opener, but an opener on a target who will not have an energy bar for at least 3 seconds (depends how fast you can get to them), and even then it starts at 0.
Congratulations, you just annihilated x class! And look! You still have 50%+ health and THEY started the fight.
*may or may not work depending on whether or not you can play your class