Here is a brief summary for those who don't have the time to read all this build.

You have to max Malefic Visions first, then Call of the Void

If the game is going bad, don't be affraid of building a survivability item between your ap items.

Try to aim well your Call of the Void in team fight, a massive silence that last 3 seconds at level 5 is a key for winning a team fight.

The sixth item you will take is a choice between Thornmail Warmog's Armor Banshee's Veil Zhonya's Hourglass.

Hi everyone ! This is my first guide featuring "Malzahar The Prophet Of The Void".
In this guide, you will learn a nice way to play a funny AP carry. The way I play it gives him as much burst as other build, but with much more survivability as you will see.

Just a little thank you to jhoijhoi's Making a Guide page that helped me a lot

http://www.mobafire.com/league-of-legends/build/making-a-guide-101506

Pros : - Awesome nuker - Mass silence - Can beat any mid at 1v1 on level 6 - Anti-Tank - Great ability to farm- Incredible mid
Cons : No escape machanism - pushes lane very quickly early game - Ultimate very tough to land in a team fight

I go for a standart 9-0-21, reaching the 15 % magic penetration in offense tree and putting the rest in utility

Flash I dont have to explain why taking this spell ?
Ignite Coordinate very well with Nether Grasp. I explain, when you land your ultimate, be certain to be in range to cast your ignite during it.
Ignite

ISN'T INTERRUPTING YOUR ULTIMATE

Ghost Could be a good choice, but in my point of view ignite is just too good with Malzahar

I can't see Malzahar with any other spell then these 3.

Greater Mark of Magic Penetration x9 Magic Penetration is just too important for caster
greater seal of replenishment x6 Gives an early game mana regeneration to help you spam some spells to harass.
Greater Seal of Scaling Mana Regeneration x3 I chose to put 6 flat mana regeneration and 3 per level to permit me to get a late game bonus for the little moments you won't have a blue buff.
Greater Glyph of Ability Power x9 I find these runes good for Malzahar because it permit you to be sure that your level 6 combo will down anyone, even tanks.
Greater Quintessence of Ability Power Same reason as before.

Optionnal Runes

Greater Glyph of Cooldown Reduction Could be good for end game, even though you should always have blue buff mid and late game, this buff grants enough cooldown reduction for you.
Greater Quintessence of Magic Penetration Also a possible choice.

I won't hide it, I am not a fan of Doran's Ring, i just find it is slowing your normal game. Early game is a farming time, no need to get this item because you will only be farming and harassing a bit.

My first item Sapphire Crystal with Health Potionx2 is good against almost every mid. The only exception is if you mid against someone like Anivia or Lux or Karthus or anyone that you have difficulties to deal with, don't hesitate, Boots and Health Potion x3 to not get harassed early.

Begin by building Rod of Ages, which gives you enough mana, extra health, and some ap.
Many Malzahar are building Archangel's Staff, but you don't need extra mana instead of health ... your Malefic Visions regenerate your mana so fast. Rod of Ages is just the best early game item.

Sorcerer's Shoes Standart caster boots

Will of the Ancients I first got the idea from xPeke, from Fnatic team, who used it on Malzahar. In a team fight, you are usually focused first. So you spam your spell and get out of the fight, but there is always someone or even the whole team chasing you. Just land a Call of the Void and a Null Zone and your health is now full ! An other utility of this item is when you want to farm a minion wave, Malefic Visions bounce from minions to minions giving your health back very fast.

Rabadon's Deathcap Ability power is just a must with every caster.

Situationnal items

Seeing how the game goes, you will have many choices for your final item.

Warmog's Armor My favorite item. Much extra health, almost always my fifth item. Seems to be a strange idea, but it works pretty well.

Thornmail Against an heavy attack damage team, always a good choice

Banshee's Veil Against Veigar or LeBlanc or any other caster who is just focusing you in team fights.

Zhonya's Hourglass These games when everyone is just jumping on you and doing their 5 ultimates on you to take you down...

In some little case, Will of the Ancients is better taken before Rabadon's Deathcap, for exemple if you see that someone in your team has alreay one, 50 % spell vamp in team fight would be devastating.

An other option is to take Hexteck revolver if someone in your team has Will of the Ancients, then rush your Rabadon's Deathcap and then finish your Will of the Ancients. Adapt your item choice to the game.

Summon Voidling Nice spell, helps a lot early game to harass an other champion. Have in mind that your voidling will always target first an ennemy who has Malefic Visions. At the beggining of the game, do 2 or 3 Call of the Void in your base to stack this passive. This passive permit you to be one of the best ap carry to push a turret early game. Once you killed the mid, or for any reason he isn't there, push quickly with your voidling. This voidling is also a great thing for your team mid-late game, you begin to tank a turret, you spam some spells, you retreat, then the voidling is tanking this turret.
An other important thing to do late game is to spam spells while pushing turret, voidling damage to turrets is complety ridiculous at level 18, making 2 or 3 of them appear could be a nice trick late game. An other thing very nice of this passive, it can block skill shots, like snares, if you are lucky !

Call of the Void Mass aoe silence doing great damage. Try to place it just a little farther then your ennemy is, he will get the reflex when he is this spell landing to go back, just where you placed it. If your ennemy is completly on the side of this spell, it will only do half damage, but will at least silence the ennemy. It also reveals the area, you can use this spell to check bushes or to harass over walls. Don't forget, this spell silence from summoner's spell to, it means when you see someone low life getting chase that seems to want to Flash, land it so he won't be able to. Nice harass spell when all the ennemy team is turret hugging.

Null Zone Great spell to down easily tanks. Also great damage on neutral mob like baron. This spells can also be leveled up before Call of the Void against a team formed of many tanky dps. In team fights, this spell can do such a big difference if well aimed. Imagine, more or less 10 % of everyone maximum health each second, that hurts ! That spell can also be used when you chase someone with almost no health, because it has much range, permitting you to just land it and kill someone very low. I have seen many Malzahar farming minions with this spell, but it is not a very good idea, Call of the Void and Malefic Visions are the spells to farm because they are more effective.

Malefic Visions Great damage, bouncing from ennemy to ennemy, giving your mana back. Combined with your voidling it is such a good early game harassment. At level 5, this spell combined with your pet can clear as much minion waves as you want that easy. Try to avoid cannon minions early game, because you won't be able to transmit this spell over an other minion.

Nether Grasp Such a great 1v1 ultimate, but such a tough spell to cast in team fights. Try to use it when ennemy are escaping, because when you will cast it, all the ennemy team will jump on you. Try to cast this spell on the other team ad carry or ap carry, depending of the game situation. Don't be affraid of interrupting your ultimate to Flash and then get back in the fight when you know they are focusing you. When someone is diving you over your turret, make your fast combo and use Nether Grasp to get an easy kill while the turret is just pawning them !

Harassment Combo : Malefic Visions with your voidling or simply Call of the Void

1v1 Combo : Malefic Visions Null Zone Nether Grasp Ignite

1v1 Combo against someone with a silence: Call of the Void Flash Malefic Visions Null Zone Nether Grasp Ignite

Dragon/Baron Steal Combo without Clairvoyance : Call of the Void Flash Null Zone Malefic Visions

Dragon/Baron Steal Combo with Clairvoyance : Flash Call of the Void Null Zone Malefic Visions

You got one chance on two to steal it, these 3 spells deals ton of damage and are applying there damage at almost each 0.2 second, which means there is a great chance to steal these monsters.

Level 1 to 3 : last hit minions, harass with some Call of the Void when your mana is almost full.
Level 4-5 : Do the harassment combo but don't forget to last hit.
Level 6 : If you think you can kill your ennemy do it, or just go gank in an other lane if they got some troubles.

Each time you back to base, always take a ward and if possible one or two Health Potion and Mana Potion

If you see your ennemy is playing way aggressive, try to aim a Call of the Void in his face while you are backing, if you land it on your opponnent, run at him while landing your Malefic Visions, the ennemy will now play less aggressively seing he cant harass you

Priority in this phase is just farming as much creep as you can, and killing the other mid at level 6 with your full combo.

At 15:00 if you farmed well you should have your Rod of Ages and your Boots
Every time you get a gank opportunity go for it, if not, just farm more and more. When team fights are beggining, be sure to be protect by your tank. Your job is to land your spell, then to back once you can land them again. When the ennemy team is backing, Flash Nether Grasp will give your team some time to down the ennemy champion. Don't hesiste to get out of the fight while your spells are on cooldown, and then to come back to help your team. You are the one doing in your team the most damage in the less time, you need to stay alive. Flash when they want to focus you, then get back and kill them.

At this moment of the game, your team should let you the blue buff every time it spawns, making you a pure nuke. The most important spell to land is your Call of the Void, that massive silence of 3 seconds, dont be shy to flash in to place this spell through the whole team, a perfect Call of the Void is just simply turning the fight into your advantage.
At this phase of the game, try to take some wards just before you begin your final core item, place wards just everyone to help your support. If your team is in a bad position while the other team is baronning, try to steal it, you got a half chance to get it, and if you succeed, you can completly change the game by doing so.

I want to thank you for reading this game, please test it before voting.
If you have any questions, just ask it will be my pleasure to answer.
Feedbacks are always welcome, it will help me improve this guide, so don't hesitate !

I am at 1500 elo in solo queue, and this build grants me a 80 % win rate with Malzahar in around 80 games, now it is your time to test it !