I believe that the lore of heavens is incredibly deceptive as the only thing it has against flying units is the "roiling skies" debuff.
So i had an idea of a overcast version of chain lightning, basically dealing high burst damage and leaping to other nearby enemies.
The catch is that the initial cast has to be made on a flying unit which acts as a conduit to harm other units below or nearby.

Basically like a higher cost spirit leech with some aoe damage.
Don't get me wrong, lore of heavens is already extremely strong but it really can't be said to be useful against flying units.
Sure the debuff is good if you have flying units yourself but having an actual spell capable of dealing with flyers would be great.