Malzahar the all mighty infector of space aids from the void!
this build if played right can be fun for you and devistating for the enemy team!
usually using space aids (Malefic Visions) and the three health potions in the begining can give you great early lane sustain and lane control it can get a bit pushy so just be careful you are not ganked because if done right you will have a greater control over your lane than your opponent

with the lane sustain you should have and if playing decently careful you shouldnt need to go back that often but try and be sure you are not going back to often so that you can buy at least one or more items at a time (i can not stand having to recall and not buy items)

the Malefic Visions or as i call it space aids, is a great sorce of damage and mana replenisher be sure to use it on minions alot and continue attacking each minion with space aids inflicting them if it passes through the minion wave quickly and your opponent isnt paying attention it will inflict them eventually!
you can if you want but i do not use call of the void that often untill later but its good to take early to help cut minion health for space aids or to silence ganks to escape easier.
and lastly the normal combo null zone and nether grasp is great for making any oponent rage!
i usually if possible open and advance with call of the void, space aids and ignite then place null zone under them and nether grasp them if you can successfully do this combo it will literally almost wipe out ANY other champion
this is because they would have 6 sorces of damage hit them and 5 of the sorces being a continuous damage output.
the 5 continuous sources are the ignite, space aids, nullzone, nether grasp, and your voidling hitting them because your passive had been engaged after using your 4 abilities.

Flash of course i usually use for a defence to get out of a gank or sticky situations

ignite is to drain their health with the rest of your champion abilities

pros:
you will be able to 1v1 almost any other champion and win if not interupted

massive damage output and massive farm ability

Cons:

pretty much a glass cannon so be carefull

the combo of 5 things can be really tricky to land all spells and abilities

and sort of fear, stun, toss, etc... can stop your ult almost ruining the whole combo

malzahar can be one of the most feared champions in the league of legends, he just has to be played correctly and no one will stand in the way of the prophet of the void and his voidlings