Draco is talking about using the spell "Channel" and then using the settings of Disable Other Abilities in conjunction with a Follow Through Time that will allow your unit to play its whole animation.
This will basically cause the unit to cast the spell and be pseudo paused until the duration is over, thereby not allowing other skills to be used or cancelled.
However, I was under the impression you could just use a Follow Through Time or Art Duration to display a unit's animation.