I will agree with xray on this one. It's far too situational and really would only find a niche use in maybe Water decks with Air splashed in.
Try to make it broader and less confined. Right now, you have sorta stuck it into an element which it doesn't help very much. Flooding is not very well used and doesn't have any "sky spells". Which means this is essentially a pillar for Water that costs actual quanta.
Now, if it were in the Water/Air duo, it would still see little use. Water's need for Air is slim. Water already has plenty of CC, which means the card that benefits from this is unneeded in Water anyways.
Say Water/Aether then. Again, Water's need for another element's CC is slim. It would prefer PC from Fire or healing from Light, etc etc.
Also, if you make up a term (like sky spells), then make sure you include every card you intend to be in that category. While you may think it's obvious, it's better to leave no gray space at all.
