I really dont know what relevance bringing back thorn has to the Rise of Iron's story. It's a annoying handcannon that was first wielded by a guardian turned killer, then by thousands of people who needed a crutch to compete in the crucible instead of finding their own way to victory. I'll accept that for some reason the thorn is coming back, but it was, is, and always will be a weapon for the unskilled lowlifes of the crucible.