• Use "Starts the effect of an ability" as an event.
• Don't use Waits, in global handling, it won't be MUI.
• It leaks; "Position of (Casting unit)", "Position of (Target unit of ability being cast)".
• Use "Triggering unit" instead of "Casting unit": It procs faster.
• Way too simple; the spell is consisted of 4 lines :/