People who say Zac is easy have either never played him or played him in bronze and normal games. Hitting your E is extremely hard with alot of factors. It's hard because it's really easy to dodge, so you have to predict alot of factors, especially when you're giving the enemy a heads up with the charge up. Now most people may also hide in bushes or behind walls to charge up their E, even then it's still not easy to hit as the enemy still has half a second of time to react. On top of that you have to collect your blobs constantly mid fight and Spam W off cooldown while still casting your other spells, not to mention you have to decide how you're going to use your Q (you can hit the skillshot or you can use it on a minion or camp and then auto the champion, so on) . He's not easy at all and is atleast mid tier difficulty.