I was so excited to play ZAC on the PBE. He looked awesome. After waiting a terribly long queue, I start a custom match to test him out. He's got awesome animations and his voice is amazing. He's a manaless, tanky, AP based champion. Or so I thought... His abilities cost health to use, but not a flat amount of health. They cost a percentage of CURRENT. His Q costs 6%, his W 4%, his E 12%, and his ult has no cost. His passive makes little awesomely animated goo globs fly out of him if he hits an enemy with an ability. These goo balls fall to the ground where Zac can then pick them up to regain 4% of MAXIMUM. While I thought this wan't too big of a deal, since his abilities cost less health the lower he gets. The problem is, he does not do enough damage with his abilities for them to be worth using. If you go all in on a champion, you'll end up doing more damage to yourself. Some might say that this can be compensated for by the passive globs, but in a fight, you don't have time to get the globs. The globs are not like Draven's axes in the sense that they fly to where you are going. They just go anywhere they please, and to top that off enemies can destroy the globs by walking over them. I was reading over some posts about him, and I found the excerpt below from someone's post.

ZAC's kit is quite good in my opinion. The cost of his abilities just need to be worked out. I understand that he is still in beta, so I'm not too upset about it, but something must change. Feel free to add your opinions!

I've got to say he sounds extremely close tot he old mordekaiser i think i'm going to enjoy this champion a lot, (max armor/MR and some spell vamp/health regen avoiding extra hp)

His main problem is the blobs. All the Champs that use HP have something to make up for it like Mundos passive and ult, Vlads drain and spell vamp + his passive gives him a lot of hp for damage. Zac does not get rewarded for building more damage then health like Vlad does and his blobs are not the best for HP recovery in a fight. One of his skills needs to be that he gets more hp regen or something the higher lv it is. This passive on a skill will make sense for his character because he is a blob so why can't he regrow his damaged parts.