This is a fantastic card that joins Air Supremacy as a good reason to pair Leadership with your Aerial hero. They play well together, in fact, since Supremacy helps you dish out damage if minions are your threat while Cloud 9 gives you a burst of thwarting to answer multiple schemes. Cloud 9 plays well with ready effects such as Command Team or even Get Ready since her pump ability doesn't damage herself. Whereas these ready-ing cards usually don't provide extra value and just speed up your ally's uses before they die to consequential damage, Cloud 9 actually gets extra activations from them.

Look to Adam Warlock, Falcon, or Captain Marvel to fill out your Aerial allies. Falcon, Vivian, and Snowguard (on 2) are additionally Champions which may help your other synergies.

Has to be built around for good effect, but a solid card!