I don't think the skill works as intended at all.
The fextralife wiki mentions this:
"Despite not being mentioned in the description, when cast by player characters, this skill appears also deal an initial hit to all characters in the area that varies from 100% to 250% weapon damage. As such, this skill is a very strong AoE ability for its AP cost and short cooldown."
Now here it says something about pcs, but as you mentioned the AI casting it actually has exactly the same effect.
