So I heard from a friend in the game about this glitch and thought I might as well show it to people who don't know how to do this.
The glitch occurs when you cancel in the middle of a casting animation, and when you switch channels it will be off cooldown once again.
I show in this video how to do it, and it can be used to kill a group of mobs, then switch back a channel and kill another group, or it can be used in defense on a temple on stones, then run away and switch channel. Come back and cast again . Still costs caelium pieces and mana however.
1.Cast Volt rain anywhere you want
2.Cancel in the middle of casting time before the entire skill finishes
3.Switch channel when you are able to
4. Volt rain is off cooldown for you to cast again!
Here is the video showing it for people who want to see!
Aika Glitched cooldown VR - YouTube