Problem with abilitie

[italocolt]

Look this trigger:

• Events
  • Unit - A unit Starts the effect of an ability
  • Conditions
    • (Ability being cast) Equal to Atacar
  • Actions
    • Unit - Cause (Triggering unit) to damage (Target Unit Of Ability Being Cast), dealing (3.00 x (Real((Strength of (Casting unit) (Include bonuses))))) damage of attack type Spells and damage type Normal

but the ability "Atacar" is one "Elunes Arrow", and to the target unit lose 3x str of casting unit, I need click on a unit, but... if this unit is running, I will need target the ground in front the unit, to the arrow take in the unit, but if I click on the ground, the target unit dont will lose 3x str of casting unit...

 

[Executor]

And where is the "Elune's Arrow" implementation?

 

[italocolt]

What implementation??