SerbianBeast, i think casting time DOES NOT play animations?
Get the Channel skill and set the channeling time to 10, not casting time.
Use an event "When a unit finishes casting an ability" and create a dummy to cast watever u want.
However i dont think the event would trigger Event Responses like Target Point or Unit. So its better if its for a Non Target spell (Feral Spirit etc). Btw, wahd u nid a channel and then a Rain of Fire? Ridiculous... and u have to use a more advanced trigger (too lazy to write) for point/unit targeted spells like that/.