[General] How does one make something similar to "Is Attacked" but for spells/items?

[skemmerblef]

Hi -- I created an item which casts a spell, mimicking a ranged attack. You click the item in the inventory, click the target, a projectile fires and it deals damage. It's based off of Shadow Strike. All is good there and I'm having no issues. Hooooowever...

...it isn't triggering this trigger!

To my understanding, "is attacked" triggers when you tell a unit to right click something and it swings, so it makes sense for an item not to trigger it. That's the problem... How can I make an event as close to the pictured one as possible, but have it trigger when I use an ability or item on the unit?

 

[Nichilus]

What you are doing is casting the item's ability. As such, you should be able to detect this event via "Unit - a unit starts casting an ability"