I am not sure how to implement this, the idea just sounds really fun so hear me out. We already have tornadoes as a Barb mechanic and now a weapon throwing skill just got introduced. What if we could throw weapons into tornadoes that would spin them and do extra damage or apply effects to enemies. Maybe a unique that unable this, slow tornadoes down make them larger but less of them would spawn.
So a copy paste from Druids?
To me it sounds like Ravager, which is something WoW Warriors have from time to time. You throw out a big axe and and spins in a circle, hovering above ground.
It started off as weapon proc, and later Nazgrim had it when you fought him in SoO but they turned it into a skill after a while.
Druids have Hurricane. Boulder can spin around Hurricane. Sounds just like what TC said.