Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Threats to Malzahar with this build
Its allways important to wait for a good stun. you can easely farm save midlane with your E and wait for a gank. mid to late game its important to poke with you Q, try to hit the void beneath as many as you can and use your Q to silence them all. Use your E on a midlaner or ADC and ult him, when you get the kill your E will instant go to the one who was closest to that champ.
don't forget you have low CD on that E and you can use a second one on another champ.