I grok do u |
...whenever a mortal usher deals hit point damage by using the attack action, casting a spell that targets only a single creature, or throwing an alchemical item as a standard action (including an alchemist’s bombs)
I don't think using an attack of opportunity qualifies here. Even if reaping strike can usually be used with vital strike (as part of an attack action), it doesn't necessarily follow it can be used as part of other special abilities that allow vital strike like vital punishment or Gorum's swordsmanship.
AwesomenessDog |
I agree with the above but will add that the wording of Reaping Strike was clearly meant to exclude things like AoO, not because you can only do it with a standard attack action, but to prevent builds that cheese looping AoOs or other AoO spam from getting this ability in off turn attacks. Just because one ability gets around the limitations of another feat, doesn't mean it gets around another ability's limitations even if they sometimes overlap.