Usually I pull bosses with it and an AS. Except the 2nd boss in shattered halls(maybe there are other bosses but this one comes first in my mind). But sometimes I feel I should keep it when a dps is getting closer on Omen or when I go oom. But I'm not sure it's good to pop wings when going oom cause I can't spam everything, so I lose a part of the 20 sec.
_________________
Naxxramas










