Ekko's kit is pretty damn good?

Yes, I am aware that I'm a low level scrub who is not entitled to an opinion and should GTFO til I'm Gold, yada yada. Yes, I also know I suck at this game. With the usual degrading comments aside, I want to point out the "theoretical" power of Ekko. Simply looking at the PBE, Ekko seems pretty amazing. Ekko's passive is great, granting a slow and extra damage, as well as stealing movement speed for himself against champions. So this hands Ekko great kiting abilities. His Q gives his an excellent poke, akin to that of Sivr's, except even better, as it even hits creeps... twice. However being AP based does not give him particularly that big of an early game lane advantage. Also, it slows enemy champs, leading to being almost impossible to give chase to Ekko. Give him Frostborn Gauntlet and suddenly you can't run from Ekko. Although I see champs immune to slow being Ekko's bane, (cough, cough Master Yi). I could see an excellent turret diving with the use of Ekko's W and E. Ekko's W sets up a slow field, and naturally combos with his E, in where Ekko dashes a short distance in the targeted direction, dealing bonus magic damage and teleport him to his target. And when Ekko enters his area of W, he will detonate it, gaining a shield that absorbs damage for 2 seconds, protecting him from turret shots. Did I mention that Ekko also has a passive with his W? Ekko's basic attacks deal bonus magic damage to enemies under 30% health, helping Ekko chase and kill with his Q and passive. Enemies caught inside are stunned for 2.25 seconds. If the enemy isn't dead by then, simply moving away from the turret and harassing with his Q or AA should kill them. If the enemy is a tank or somehow managed to escape, the ally jungler has a perfect opportunity to secure a kill. Drawbacks in Ekko seems to be his generally squishiness, and the difficulty of his ult. Ekko's ult is strange, situational, and gasp requires skill. Ekko's ult makes him invulnerable and untargetable, and teleports him back to wherever he was 4 seconds ago. Ekko heals himself and deals magic damage to all nearby enemies on arrival. Most people would use this merely to hit and run, to disappear from a teamfight. Do it wrong, you end up nowhere, or worse, in the middle of the enemy's mid lane push. Do it right, and you could win yourself a potential penta, or at least win teamfight. Note: This is my own speculation, before Ekko was released. Also thanks to Surrender at 20 for the information.

tl;dr Ekko could be a better kite than Ezreal. Ekko can turret dive. Master Yi shuts down Ekko's squishy butt. Ekko's ult is weird.