My summoner name is OVOmilkduds. First guide I've done. I'm a Bronze 2 mid-laner. Ekko is the first champion I played, and the champ I main still. Up to 182k xp on this beast. Ekko is filthy. He has 2 slows, a stun, a gap-close, and a re-do button. 2 of his 4 abilities are AoE, he has single target damage, he scales as well as anyone in the game, but isn't a liability early, and he's so mobile it's not fair, particularly in the late game. A 2 second stun that you can proc on possibly the entire enemy team (in the right circumstance) can chance an entire teamfight without dealing one damaging ability. Ekko can be run the same way top or mid, though I prefer mid. I don't believe Ekko has a counter when played properly. His Q evens out range differentials against mages, and can poke down melee champions just the same.

Lv2 combo is E in, and throw out a Q, AA, and let the Q return. If you Q during the second dash of your E, the Q animation is hidden, and can't be dodged. Lv3 on, hide from a bush so your W sound effect isn't triggered, or QW to hide the W sound animation. If your W isn't heard, and is placed properly, you should trigger a stun or a flash on most occasions. The full combo I hit mid/late game is an E in, W on top of yourself if they immediately fight, Q, AA, let the Q return, Ulti, E, Q, AA, Q. If they aren't dead, you're probably fighting Nautilus or Maokai, and youre still at nearly full health.