There is no cooldown on the stun (E) on Udyr. Meaning: he can stun someone infinitely just by basic attacking them.
It only works ~~on Spirit Guard Udyr.~~ if he has _Manaflow Band_.
Rumors also went around about a bug on Annie's stun and something was wrong with Thunderlords, but I have yet to find any issue with the champion and the rune.
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