If any champion has ever deserved a knee-jerk, it is Ekko.

It really doesn't take long at all to any competent league player to see how Ekko's kit has all the benefits but none of the drawbacks.

Let's take a look at his passive... 40% slow, 40% ms buff for 2 seconds, 30ish base damage and a 70% ap ratio at level one. "But faps, Ekko has to land 3 attacks/abilities to proc it." That's true, but unfortunately, he has a boomerang ability for double procage. At level one. Completely invalidating this even being a factor. God forbid he gets past level one and it scales up to the ridiculous 80% slow/ms buff. This passive all by itself completely invalidates you if you do not have ranged abilities or some mobility available. Tryndamere without your spin? Sorry, your ults gone by the time this slow is over. Darius ever, guess you can't play him anymore. Survive a Jax jumpstun? Completely useless. This isn't even the worst part, trust.

Let's look at his q... I honestly would not have any problem with Ekko's Q at all if his passive didn't exist (except the base damage is a little high for the scaling it has). Ekko's q is pretty balanced ability, though impossible to dodge at low range. It does a little over 300 base damage with 80% ap scaling with a slow attached. Pretty generic, but hey, it's not that bad. His passive just makes it so damn frustrating just because of the sheer kiting/chasing/burst it gives. Fix the passive, fix the q :).

Let's look at his w... An aoe slow/stun field with a 3 second delay. Perhaps the most frustrating thing about this ability is the lack of visibility.
Taken straight from the wiki "Enemies do not gain vision of the target area until the last 0.5 seconds." .5 seconds is hella short of a time frame. If Ekko is ganking another lane, he can dashblink directly up to someone and almost garuntee a stun, if not, a flash or some other escape. If he plans to engage, he can use his w, wait 2 seconds, then do the exact same thing. The visibility of the ability could really use some tweaking. Shaco's cloud can be seen from the fog of war, why cant Ekko's little hologram thing be the same way? Why can't the stun scale in duration? Why does Ekko get a third slow? Why does this non-ultimate, aoe cc also get an absolutely massive shield attached to it?

Oh wait, that's why it does so much, because it has a passive too. An execution that scales and has base damage. :/

Let's look at his e... Dash+additional blink if needed. Applies spell effects and on-hit effects. Non-existent cool down at later ranks. More mobility creep in the league of mobility. Hopefully dashblink speaks for itself cuz I wanna wrap this up.

And his ultimate... A gapcloser that renders Ekko invulnerable, untargetable, does arguably the most damage of any ability in the game that doesn't have a channel linked to it thanks to its 130% ap scaling and considerable base damage, aaaaaaaaaaaaaaand heals. Way to once again stuff an ability with everything you can think of that works in its scenario. I recall some rioter in the patch notes making a remark justifying the olafing of veigar saying something along the lines of: "We don't like it when a character makes a player say 'oh, I'm dead' instantly with no counter play." Well now it's aoe and a heal on top of that. Oh and no mana cost, for no reason at all. Let's make more characters that use mana as a resource, except don't actually use it. The Fog of War once again hides his ultimate (which is understandable in one way, since showing the path you took to escape could be fatal), standing near him as an immobile melee for too long enables him to use it to blink 0 distance and hit you, and he has the means of keeping you where he wants when you're an immobile melee due to his ridiculous passive. The zoning potential on this ultimate is massive, and even then the zone isn't easy to follow, making enemies have to consider the zone larger than it is in case they lost track of how fast he was moving or whether he dashed.

An assassin, of the most basic standards, blows his or her cooldowns to get in and kill someone, and leaves. Bad play leads to their certain death, caught without abilities to use, and good plays may get them another kill on top of their main target. They tend to be good at picking people off, or zoning/killing "important" figures in teamfights with the help of his or her initiator. Ekko does all this and more; He has point and click dashing for the all-ins, decent burst, cc, shields if he played his cards right, hard cc of ridiculous proportions (meaning he can initiate in non-5v5 fights all by himself), can peel for himself, can support his allies by slowing anyone chasing them, stunning anyone chasing them, can take a hit, and can reliably escape on top of all that.

As a character, his early damage is obnoxious. He can easily jump in on a Mordekaiser and fight him outright at low levels, face tanking damage and making Mordekaiser unable to walk away due to the ridiculous slow. The only characters that can face him are the already-problematic ones like Leblanc and characters that can out-stat him. Many say that all you need is to do more burst than he can, but that's a silly proposal in and of itself and is not counterplay, it's just out-statting a character. Mid and late game, most of his damage is front-loaded onto point-and-click, much like how TF puts all of his damage onto this yellow-carded right click to do nearly his entire burst. It's not easy to dodge, I'll tell ya that much. While Ekko's click-to-kill combo isn't strong, it's still all loaded onto a click. Mid and late game, burst characters also get up to snuff and are able to combo people to death from a CC move. Ekko invalidates them by making it so that if they fail to kill him instantly enough, he R's away, and his R most likely has a lower cooldown than yours mid-to-late game.

I make this post in hopes that some people (including you, Ekko spammers) will come to realize just how frustrating Ekko is to play against. No character should have this much in one kit. No character should have that ultimate. I don't care how high the skillcap is, but this champion, and champions like Ekko, are making this game increasingly difficult to want to play for fun.

I have no idea how one can go about reworking this. The easiest fix would be just deleting him, but I don't think Riot likes to admit they make mistakes, so that's not gonna happen.

tl;dr Ekko has so much that makes him unfun to play against and has all the benefits with no drawbacks. Just in general needs some serious attention.