Are you planning to include new abilities that would require new animations such as a whirlwind attack with the sledge? This could be done by altering the power attack abilities.
I could easily see an ability option that gives the player a version of the zombie rage mode for 10 seconds or something after a power attack. These kinds of things would absolutely be insane and make finding legendary items ♥♥♥♥-your-pants worthy.
Loc