You are not worthy to fly

All flying creatures had an advantage over those who couldn't climb to cloud level - safety.

Sure, monsters like the One-Eyed Serpent Archers or Phantoms with long-range abilities could do something to the flying monsters, but more often than not the flying ones would simply dodge their attacks and move away to a safe distance.

This allowed the flying monsters to attack when it was to their advantage without taking any risks.

Thus, if a flying monster didn't need to come down to the ground for some reason and could do its job from above, it was invulnerable to ground monsters. The only ones that could attack this monster were other flying ones.

But... This was only true if, among the ground walkers, there was not one strong and brave enough, one capable of bringing the sky dwellers down to the bottom.

Ripple. Ripple. Ripple.