I know, this is an old content question, but I don't yet have this feat and I just want to confirm how to get it. The description says "Collect any 5 Sin Stones," but apparently "collect" means something specific. I had two in my bank from an earlier (much earlier) drop from an Assassin TC, but I only have credit for collecting one in my feat list. I used them to level an artifact -- no increase in credit. I bought a couple of different ones from the vendor and used them too -- no increase in credit, still at 1/5. So is the only way to "collect" sin stones to open an Assassin TC and hope one drops? Like I say, just looking to confirm.
