Alistar Counters Zyra and Malzahar
After his mini-rework, Alistar's E has quietly become a useful tool in dealing with the two most annoying Mage Supports on the Rift. Yet, I never see anyone actually use it outside of the few mains that understand it.
Alistar's new E pulses around him steadily, shredding voidlings and seedlings alike. Against him, Malzahar's Passive works against him, giving the Alistar a free chance to screw up the headbutt/pulverize combo because his passive will block the knockback and fall off. Engaging on him is a simple matter. Malzahar will naturally try to press you early, giving you ample opportunity to punish him for it with a counter-engage.
Against Zyra, it's a far more simple matter. Her plants barely hurt him to begin with early game, and Zyra will grant you level 2-3 as she needs the time to get rolling herself. Even then, you can simply waltz through her plants and engage her with her kit fully expended.
I am, admittedly, bad at Melee Supports. But even I have found easy success in this counter. I find it amazing that the "pros" don't use him for this end, especially when they play a carry Top Laner like Jayce or Fiora, or an Orianna Mid.