Talk:Sejuani/@comment-25532677-20150420213749/@comment-15280970-20150422133301

Because they are different. For example, Amumu's pre 6 threat consists of a relatively dodgeable skillshot that only stuns the hit target and dashes to that target.

Sejuani's Q is an AOE knockup Dash that only stops when it hits a champion.

Amumu's massive AOE damage doesn't have a consistent way to be dealt pre 6, he lacks an AOE slow.

So, both sejuani and Amumu deal massive AOE damage, but sejuani has all the tools to abuse that damage early game and then consolidate that early advantage in the form of more damage and tankyness (cinderhulk).

Then, amumu has always had a high win rate and people know how to play against him. Sejuani has always been less popular than our mummy, and the effectiveness of using (abusing) her is higher because of that lack of knowledge once you learn how to use her.