With those recent Malzahar changes I must say, I miss old Malzahar. His old self didn't had this passive which is awesome to protect him from many of its old weakness, mainly initial burst damage, all-ins, crowd control, and ganks. However, he also did a lot more damage, wasn't weak early game, didn' had massive mana costs, and wasn't reliant on his voidlings to do damage.
The only reason why new Malzahar succeeds is because of this broken as fuck passive. Malzahar himself may not be broken, but his passive surely is. 90% damage reduction coupled with immunity to CC, even though it is easily broken at late game, it is just as easly regained. This is the only reason why Malzahar is good since his damage has been significantly nerfed compared to his old self. Q and E had its ratios and bases nerfed, W is now a completely different spell, and his new R cannot be compared to his old R.
Also, Malzahar is very weak early, and his mana costs are higher. Old Malzahar was strong early game because of his old W, his ability to push early without a lot of AP, and his abilities had insane base damage. At least new Malzahar is safe from ganks and all-ins because of his passive, but whenever I play him I struggle a lot until I can complete Morellonomicon + Rylai, whereas with the old Malzahar oftentimes I would not even use mana items on him at all and I would just rely on 2 dorans and straight up rush Rylai for even more early game power. I can't do that with the new Malzahar because his new E does not recover enough mana to allow him to work without mana items, he absolutely needs Morellonomicon now (either that or Rod of Ages, but on my opinion Morello is better due to the CDR, new Malz is a lot more CDR reliant than old Malz).
Riot keeps talking of how much old Malzahar was unhealthy, but on my opinion new Malzahar is the unhealthy one while old Malzahar was perfectly balanced. Why new Malzahar is unhealthy? Well, he has a broken passive, but the rest of his kit is below average in terms of damage. This means he is relying on a broken mechanic to allow the rest of his kit to work, but the rest of his kit has to be nerfed to compensate, creating a situation where Riot might as well just nerf or replace this passive with something healthier then buff the rest of his kit.
At least his abilities synergize with each other, but when compared to old Malzahar, they don't feel as rewarding. Riot keeps talking of how unhealthy was that old Malzahar could 100-0 you, but trust me, he could never do that if you was smart and had a QSS. Nowadays it is worse because with or without QSS, Malzahar cannot 100-0 anyone that isn't incredibly squishy (that is, lacking any sort of tankyness).