While playing as malzhar in the early game, i suggest you just farm it up and engage on ganks, You should get some ability power to do lots of damage before actually trying to get an early kill, but if you can get an early kill that also good
later in game your combo would be the activate your q and you can keep harassing with e and w
or your full combo would be e silence with q then w and ult them on the pool
Then you can finish them off with your q and e and w when they are off cool down. Best thing to do would be harass them till they are low first before asking for a gank.