I agree with the multiple voidling idea. I would say make it so that the number of voidlings is upgraded with your level, 1, 6, 12 and 18 would 1 through 5 voidlings, and then make it so that their health is equal to a % of your mana pool, and their phisical damage stack with your ability power. If this ends up throwing malzahar in the wrong direction then i sugest to rework his passive entirely. but yeah making voidlings sapawn like that i would think that allot of malzahars would get aegis just for their lings to get the extra damage.
To the folks that say it's not a solution to a lack of escape mechanism, it isn't meant to be. And it's not going to provide enough extra exp/gold in the early game to create the problem of him helping the opponent to farm.
And it's not like you can stack Aegis, Starks and Locket to be viable. You could only afford 1-2 of those items because you would undoubtedly need Warmogs, Lichbane and a CDR item, probably Soul Shroud or Nashor's Tooth.
If you have an army of voidlings tower diving becomes a more appealing idea *when you want to do it* because of the extra damage from the voidlings, but you will have the inherent hazard of pulling all the aggro (hence you need to stack HP)