I've had the Thorn bounty for a few months now. I don't play crucible as I'm not much of a fan, and would rather spend my time running about raids etc. Today I decided I'd give it a blast as the hardcore PVPers would be shooting it up in the Iron Banner. So my word of crota, swordbreaker, corrective measures and I ventured into rumble for some free for all. 2 hours and only two controller throws later I crawled out battered and bruised from the Crucible with the Crucible kills complete. Think I even managed a top place finish in amongst it. Just need to go beat that wizard and I've got the thorn. Long story short, if you're having trouble doing the crucible part of the bounty, get yourself in there while the goings good!