It seems impossible now to get the ring on many characters on the same account. You beat 1 boss and relog and they are all gone. An alternative would be to make the rings tradable only through storage.
It's definitely possible to do 2 within a single spawn, 3-4 if you're willing to put in more time. It's once every 4 hours, so if you're diligent, you can get the ring within a week on 3 characters. Even if you take your time, you should be able to get the ring on all 6 characters within the month they gave us if you planned accordingly. Just get into channel 1-4 early, and you should be able to catch another round or two of Pierre killing.
Don't give up because you have a couple of bad runs now, it is the first weekend of the halloween event with new prizes added of course its going to be crowded. But I think it will slow down a bit eventually when people have got the items they wanted.
