I use my Titan for PvP most of the time, but I do have a hunter, and for PvP I run blade dancer (actually, I use different subclasses for all three of my characters in PvP and PvE: Titan - Striker for PvP, defender for PvE; Warlock - Sunsinger for PvE; Voidwalker for PvP). Anyways, RT can either make you invisible (only need to press it once) or unleash some chain of lightning on the ground. I've found that the insane slash and dash resulting for spamming the bumper results in better results. For me anyways. Perhaps you know something I don't?