Hecarim's E is the most frustrating thing in the world.

Hecarim's E, Devastating Charge is the most frustrating ability in the world for root-based CC champions. Unlike (I'm reasonably sure) literally every other champion in the game, a Rooted hecarim (through an ability like Light/Dark Binding, Flame Chompers!, Yordle Snap Trap, etc.) can still lunge 325 units, and knockback an enemy champion. This leaves basically zero counterplay for champions that peel for themselves using movement-denial abilities.