Seeing how poorly drawn out this ability is atm, here is a list of what I think should happen.

Reasonable nerfs:

Option 1: Goes through 50% of armor down from 100%

Option 2: Dragon Roar's CD has been moved to 2.5 minutes but is now off the GCD (not sure if already is)

Option 3: You can no longer use Dragon's Roar while Recklessness is in use

To be honest I think that we could agree that these are very reasonable nerfs. (Unless you are a warrior)