Also i specifically say that i donot think spirit visage is worth it on zac, which it isn't.

Honestly, if you get to the point where you're going to be building the LAST items i listed, something went really wrong all game with your team. Building armor that late is not going to stop an ADC with a full build at that time. Game shouldn't go to that point.

What's wrong with this guide:
-Cooldowns- Ionian boots,Spirit Visage and Spirit of Spectral Wraith combined with sorcery mastery is 49% of cooldown which is still 40% as it's maximim so I consider it a waste especially that U didn't invest in tenacity in the mastery tree meaning mercury threads would be so much better
-Zac won't benefit from Rabadon's that much Id rather change it for Liandry's as it stacks nicely with W and Rylai's
- Aegis is pointless, u have lots of MR from Abyssal Scepter and Spirit Visage but you lack armor, I'd replace it with Sunfire cape or Randuin's omen.
-Maxing W is much better for jungling than maxing Q first, W has low CD and Aoe damage+ it is pretty useful with damaging while ganking so i'd rather add one point in Q for slow

-1 cuz first day Zac guide and ugly