Zilean has tons of damage, scaling, utility, and maybe the best cc out of all the mid laners. I'm putting together some good win-streaks with him. One thing I noticed he has great synergies with junglers/ganking. His early game is painful (so I'm guessing that's part of the reason he isnt played that much). But, beyond that I don't understand his low play-rate.
Have you considered the glaring detail, that he might very well just be incredibly boring?
Boring AF, he has one actual ability.
How the fuck is zilean boring? You can pull off great AOE stuns, bait your ultimate, and bring a ton of utility to your team. If you play him support, he is literally the only champion that you switch the ability your are maxing midway through the game. you actually have to plan what you do during the game. Not only that but you can zoom around the map. He is one of the most unique champions in the game.
I find him boring, but I think the biggest issue is : Making the best of his ult since you depend way too much on the ally you use it on, which is NOT solo queue friendly.
In this current era, everyone here just wants to become a Naruto wannabe, hence the mass amount of Yasuo & Zed playrates.
Well, for me, Zilean is probably the most fun champion of all.
His kit is outdated and feels awkward to play.
Q needs to be changed to auto cast at max range if you attempt to cast it outside max range.
W needs to be changed to just be a passive; i should be able to press QQ or EE instead of QWQ, as the W press doesnt always trigger when done quickly. If i attempt to use a spell off cooldown, auto use W if its up.
Just clean up his gameplay.
Not flashy to watch, boring to play, and simply that has always had some level of influence of champions being allowed to stay relatively strong without nerfs. As the boring game play deters the abuse of any of the strengths the champion provides.
People said the same thing about my 
. Dont worry about it. Enjoy him! I might consider picking him up for season 10, we'll have to see. I gotta practice him a bit more
