Farm up a roa and a banner of command by the time third blue arises (15-16 ish minutes hopefully).
Tell your team to come mid while you go do blue
???
Take nexus
Abuse the fact that you can solo dragon with full health from like level 5 and up to your advantage. By taking any opportunity of map control to just go do dragon with a jungler or bot lane.
Legitimately the most straight forward win strategy on a character to exist in this game since season one.
Like this is so good and dumb, a team could do this in a championship worlds final and get away with it at least the one time.
Sub 20 minute games is really normal for me when I don't get camped by the jungler, if the enemy team does not respond immediately to the group up (and I'm talking sub 30 second reaction, because Malzahar can take two full turrets in 30 seconds) then the game is over.
Reason: RoA/catalyst every level giving you so much health and mana, blitzkrieg malzahar loves the levels just pouring in. Active on Banner: Super minion basically, that takes turret aggro before voidlings, excuse me while I have two voidlings with 200+ AD and 1.5 attacks per second (at like level 9) freely attacking towers while something else tanks for them. And the actual passive on banner multiplicatively scales with each stage of voidlings, so instead of things being 15% stronger in total (so like oh, 120 AD voidling without it), bang, suddenly 200 AD at the 2nd stage (3rd stage is the attack speed).[this is definitely unintended, and likely won't ever get noticed unless you *******s actually start using malzahar, which, from what I've gathered, no matter how many times I tell you this guy is broken you won't use him anyway, so EZ]
Otherwise...
Just be good at farming (you should be getting near perfect CS, but sometimes the timing of Malzahar's dots deny him last hits in really almost random ways, but once you're at level 3 E that shouldn't happen), realise how to conserve mana effectively early game (it's the only time where he's vulnerable to anyone 1v1), and know how to land your Q on as many opponents as possible in any situation (that's the hard part).