Spring Cleaning (Killing?)

Spring Cleaning (Killing?) is one of the Challenges available in The Arena.

Description
"I'll be honest. We've got some spare bad guys laying around here, and we're not sure what to do with them. Do you think you could help us clean house, and make room for something new? Defeat as many as you can!"

Strategy
Again, not too difficult. Use Inspire to boost your damage. The elemental type of the enemies can be 1 of 3 types: Lightning, Physical, or Earth, and you have enough abilities to counter them.