1- Don't use (Casting Unit) , use (Triggering Unit) instead.
2- Save (Triggering Unit) into a variable instead of repeating it over and over again.
3- Your jump isn't realistic at all.
4- Use a parabolic formula for this.
5- Your ability adding and removing isnt safe at all (Look at the tutorial in my signature about Making units fly (The right way)
6- You shouldn't use waits
7- You're never adding units to the "Victim Group"
8- You're leaking "Victim Group" (Destroy it like this: