To be honest malzahar is still weak to ganks if you do it right.

The midlaner must communicate with the jungler to get his aura off, then promt to gank him. I know that passive is op, but it has a near 20 sec cooldown. You are not meant to duel him, and that was ALWAYS the counter to malz. Pick lux, or any sort of mage with poke. Or a jungler that has a hard balls engage like hecarim. This factor never changed.

Also, his ratios are so weak now. If you 2v1 him he wont able to drag at least one of you down to hell like pre-rework.