It's gonna be hard to beat a mage who's spamming Arcane Blast, POM and Mirror Images. At least until you run out of mana on the mage.

it looks like your proc casts AB 2 more times. So you could have cast AB like 6x in a row before you use the proc. So it'll take a TON of mana, but it will hit really hard.

If I spam AB long enough I'm hitting for 75k crits on my 85 mages. Which is well over what I've seen any other class do.