Sorry mate but like the post above this build is somewhat ******ed.

I can't think of one champion that will take mana regen quints, best pick is AP runes like to any caster.
AP red... meh it is better to have the Spell Penetration.
AP yellow you could swap the for mana regen and take quints as AP.
Blue for cooldowns is the only one I agree with.

Clarity? really?? Well then enjoy your death when you have no way to escape, Also Malzahar's E is pretty much his way to make sure he always have enough mana.

Items;
Will of the Ancients almost has no use on Malzahar it is better to take Rod of Ages that way you will have more HP/MP + same AP and with it you wont get dropped to the ground from simple combo.

Masteries;
Take that one point from Ember and put it for more Spell Pen.
The the points from Insight and Greed and put them into Utility Master so with the Golem's Blue Buff you will be wrecking the enemy team and will be able to spawn more Voidling if you spam enough.

-1 You should have played him more before writing a guide for him.

-1 for hail , runes and ******ed low clarity ;)

Try adding some pictures, improving your grammar, and making this easier on the eyes. Not a bad guide though, though I have always been partial to rabaddon's first and WoTA later, but that might just be me.