scr mage without blizzard!?

[Peril]

The top 9 mages on my leaderboard are scr mages that do not run blizzard, but do run immolate. Would someone kindly explain this to me?

[Nhat]

(Reposting, looks like forum got rolled back...)

They're using Belt of Whispered Secrets to apply Lightning Struck status on Deflect - so don't need Blizzard for it.