Rally

[John Doe]

Can't target a beacon if you're stunned. Mummy or Annie.

Dancing around, but not directly on top of beacon, makes it hard-to-hit.

Forgot that stuns last forever and that there's no such things as AoE abilities. My bee.

In serious, I can't see taking Rally over Exhaust or Ignite or Clairvoyance or even Ghost or Teleport in anything outside of an ARAM game for all the reasons everyone else has already said.