Autocast Spawning

[Tavaunum]

I have a Hero ability based off of Searing Arrows, called "Spawning Attack". It does no extra damage, but I have a trigger set up so a Tentacle spawns near the target unit whenever it is hit with the ability. The problem is that when I have it on autocast and begin attacking, nothing happens. The current Event in the trigger is "Unit - A unit Begins casting an ability", with the Condition "(Ability being cast) Equal to Spawning Attack". It works when you click on the ability button and target a unit with it, but not when you just attack someone regularly when the ability is on autocast. There is no "Unit has ability on autocast" Condition, and if there was, I would be using the "Unit is attacked" Event for the trigger. Does anyone have any advice?

 

[GreyArchon]

It's the problem with auto-cast, the standard triggers don't detect them.

I believe I once saw a work-around for this problem, but that's all I know- triggers are not my forte. :?