One Crit Wonder

One Crit Wonder is one of the Challenges available in The Arena.

Description
"These here monsters can't be hurt by anything but critical hits. You think you got the hang of that? That being said, they look awful tough, so I bet even a crit can't hurt them, k? (What's that, Tony..? Crits beat 'em in one hit?)"

Strategy
No need to worry about overcasting for this one. At tier 1, you have a Physical, Earth, Lightning and Water attack. At tier 2, you have two Fire attacks. The optimal strategy would be to quickly cycle throughout the bottom tier attacks (and because enemies with the same type never usually come out in a row, you could potentially get a few lucky kills in), which accounts for 4 of the 5 enemy types. BUT, when an Earth-type enemy comes in, you must quickly cast one of your two Fire-type attacks.