No other ability in the game has requirements, change reveral to be usable regardless of what your equiped with.
Also, make it so Reuse Speed lowers the time it takes for this ability to refresh, or change it to an ability like weapon counter.
Example:
30 Second Cooldown, make cast speed instant.
When the Warrior is Damaged, does Reversal.
Does Damage like it does.
6 Triggers. (like it is now.)
The problem with the ability is it just doesn't scale to current content or 90, 30 seconds is "forever", with no way to lower that, why not make your reuse speed make it tick down faster?