Like with your other resources, please fix the indentation issues when you can. I second what Aldeia said. A .gif for your preview would be nice.
A simple, well-written spell with that's easy to customize.
Approved
Edit: Apologies, noticed an issue afterwards. The spell bugs out when multiple instances are cast at the same time. The fix is as simple as removing the deallocate line from the onCastTimerExpire method. I think this line is not supposed to be there.
Awaiting Update