So we all have seen the wizards globe that slows everything down except his/her attacks. So a barbarian is whirl winding into the wizard. The wizard throws down the globe slowing down the barbarian. While she is able to keep shotting spells at the barbarian. From the videos of the spell it looked like the glode lasted quite a while. I don't fell like going into more detail but i think you get the idea.
Run circles around the orb and WW as soon as it's down.
Or maybe do some Seismic Slams and get her out of it. Sure they'd be slowed, but they are AoE, and eventually she'll have to retreat from the orb.