Malzahar is one of the greatest AP champions Mid lane and that's return to his abilities of damage and his great combo that kills anyone.
Malzahar can easily push lanes or split push in late game when he has enough mana.
Iplayed malzahar as support and he is very op against your enemy ADC when they have an AP support or malzahar is great with his abilities the most of adc lake of Magic resistance and his abilities does a lot of damage if you can success is all with the ending of ulti and ignite if needed in the combo.
His passive will gives you an advanced protection against the first Crowd control (cc) or damage. you can even dive when you have the passive the turret and take the first hit after you ulti you can drop and take the 2nd hit from turret which it will damage you because the first one will takes you the shield.

I'll update the rest later