Before I start with my ideas short brief of Storm of Magic:
1. There are 4 dice for Winds of Magic (oponent get 2 highest).
2. Magical Flux - randomly chosen Magic have boost (from +3 to +5 to casting attempts)http://www.bractwo-kosci.pl/grafika/Chaos/sm04.JPGMagical Flux
3. If your wizard is on fulcrum then your wizards can cast special spells from Storm of Magic.
4. You cannot dispell spells from SoM.
5. You can use max of 6 dice for one spell.
6. You can spend bonus 25% (added to initial army cost) on magical items, pacts and bindings.
When it comes to magic - were good.
If you play with SC - take Kairos! he is really worth his points, especially when on fullcrum (no multiwounds damage on him). He can get extra spells from every 8 lores (+ from Tzeentch), that means he always have at least one spell with +5 to cast. +6 he already have give him total of +11! now those +25 spells doesn't look so expensive.
Other tactica - get as match Slaanesh wizards as you can and spam with Slothful Stupor(5+, remains in play, target reduces his Ld to 2, gains Stupidity, cannot benefit from General or BSB).
After spaming those - all other Ld-based spells are death to enemy, especially Slicing Shards.
Second spell - 20+, remains in play, Ld -2 and you control this unit. After end of subsequent magic phase unit can test it's modified Ld and if pass it - it's not under the spell.
I do not play Nurgle (have only 10 Plaguebearers), so i didn't try Nurgle spells from SoM.
Tzeentch have good missiles (3d6 Strength 2d6, if on 2d6 is 11 or 12 then they wound automatically and do not allow armour saves) and template (big template, wound on 4+, no armour saves).
But when you cause a miscast on Tzeentch, Slaanesh or Nurgle spells from SoM your wizard take bonus S10 hit.
So what is your tactica in Storm of Magic?