The Spirit Realm

Does Overpowering Strike (increace chance of landing a stun, 1% per level) work on both melee stun (i.e bash) and spell stun (i.e cast or weapon proc) or just spell stun ? It's not very clear from the in-game description. Thanks in advance.

according to Elidroth it works on both spell stun and bash stun (sorry don't have direct quote)

and yes, its a stupid AA.