Originally Posted by
Tziva
How many you need for Share the Pain will depend on how fast you can kill the boss. If you can nuke him quick, it shouldn't be an issue. You don't inherently need any number of people.
Yes, you need six minimum for Only the Penitent.
I don't think you can solo Beth, just because you still need someone up top and below right? Also probably Shannox, because the dog will chain stun you and you'll die (there might be a trick though). I mean, those aren't need-X-minimum for achievement, but they might prevent soloing.