The guy is tanky,deals respectable damage for a tank, got a resurrection passive,can gank from the sidelines easily and without warning,can towerdive without a care in the world
what is the counterplay again?
You dodge his spells and kill him. Step on his blobs too. No one does that.
As Sion I've learned he's not untargetable mid jump. You can CC him as he comes towards you to cancel the CC of his slingshot.
Best counter to Zac slingshot(E) is Poppy W.
Step on blobs, bait bad engages, cc his E, etc etc
Specifically for ganks have your jungle be ready for a counter gank (ward their jungle to know) and then bait him to E into lane and jump on him. Works most every time.
Most Zac players will engage with E from more or less as far as they can to avoid the chance of detection. Deep wards and wards over walls (for instance, the wall looping around to river on red side bottom lane) help tremendously.
Also you are incorrect. If he builds tank, he has almost no damage. If he builds AP, he's so squishy it doesn't matter. His resurrection passive is fairly long, and you can see if it's up or not by clicking on him. Also if you get his resurrection passive down, it's essentially a kill because he will now have to play safer. Also tower will focus his blobs under towers, meaning tower dives are very risky unless you're low enough it wouldn't matter if he was Zac or anyone else. And warding the unconventional places he'd gank from helps a great deal.
Also, as with any sustain tank, Exec's Call/Last Whisper/Mortal Reminder help.
Dodge his E by watching for the shadow.
Ward near his jungle entrances so you can see when he leaves them (i.e. bush between wolves and mid-lane, bush behind red buff).
If you have an ally with a knock-up or knock-back, they can use it to stop Zac's E and negate the CC/damage.
Can easily fast his knock up
Understand where his gank path are and Ward it
Hug the walls or Google Zac gank path To understand where he can come from
Crowd control can stop him mid jump.
