Honestly I don't know how good these buffs are. His E doesn't look to be as good as it was pre-rework, it's more damage but only 10%(meaning for every 100 AP he'll have 10 extra damage, though it is a DoT so it could be a decent amount more, still though it's not going to be one of those things you drop and expect that alone to deal enough damage), but it's not gonna be aids. His Q looks better overall. His W looks like mostly a nerf. He will have maximum 2 minions at all times from what it looks like(I don't see them saying that they spawn more if they attack champions anymore, dunno if this is happening or not), they'll have 200 HP at level 18 and 50 armor, which means one auto will kill them most likely all game and their damage is lessened, they'll walk like turtles(They were slow without using E on someone and now they're slower and DON'T have extra move speed when moving toward a target).
I don't think this will make Malzahar better. He's getting some extra damage on abilities but I don't think it'll even come close to making up for the damage lost and your minions will be pretty much useless unless you ult someone. His ultimate seems like it'd be the only thing that would make him worth picking tbh, so they'd be basically making Malzahar into an ult bot again. Overall the damage was increased on his ult. Also that damage is still mitigated by MR, even if it is HP% damage, ya know. It's not true damage.
At level 6 with 100 AP you would take 275+36 percent max health damage from just the scalings lmao. Include the base damages and you are taking about 430 + 36 percent max health at level 6 now
From what I'm getting it'd be 240 damage + 12.5 per second % HP damage at level 6 with 100 AP, assuming he just didn't put in that it was %HP damage, the 240 damage is purely the beam damage, not the null zone, and the null zone is the HP% damage. If it lasts the full 5 seconds it should kill an ADC(IF the % max health damage is still applied), but after that you'll probably be pretty useless. Your minions will be walking potatoes and your E will probably still suck compared to old Malz, and your Q might be better but it's still not gonna do too much without the rest of your kit.
One thing to note, his W is no longer 4% AD but 40% AD, so there's that. His kit is still mostly made up of AP and his minions will still be turtles though so I don't think it'll be worth trying out AD Malzahar though.