Primal Hunger - Potential Bug?

Hi,

I am running a Rage Shaman Spell caster build.

To get as much Rage as possible to contribute to mystical rage and druidic champion passives I taken primal hunger.

It decreased my spells damage? I see the node has "No rage effect"
Im assuming that means the inherent effect of rage contributing to attack damage?



May not be a bug, but unsure what Primal Rage could be used for if it removes all rage effects. Maybe there is rage spent builds?

Thanks :)