15mins for 2s.
No time limit on the other brackets.
So a huge benefit to all dmg groups? Live just long enough to have dmg stack then nuke the piss out of the other group. I can only think of the 3 or 5 man stealth groups that would run around with this option. 5 rogues fight for a bit let the first shadow site come and go then mass cloak of shadows and vanish then come out of stealth in a bit with a huge dmg buff.
"Privilege is invisible to those who have it."