
Reviewed for patch 7.3d

Favorable matchup
Reviewed for patch 7.3d
7.3d takes damage against monsters away from Ekko and gives Lee Sin more attack speed per level and more base damage on Dragon's Rage. Lee can use those first minutes to invade, contest scuttle and pressure lanes before Ekko has his ultimate.
Against monsters, Z-Drive Resonance goes from 120% to 110% damage and Timewinder from 115% to 100%. Ekko spends longer on each camp: if you show up in his jungle at that moment, he either fights with the monsters on him or leaves them.
Sonic Wave damages and reveals the first enemy it touches, and Tempest reveals those it hits. Ekko relies on coming in by surprise with Phase Dive; if you tag him first, the fight starts on your terms and Resonating Strike puts you on top of him.
Dragon's Rage launches the target backward, and its base damage goes up in 7.3d. Use it to kick Ekko out of the fight or into your team; if he still has Chronobreak, remember he can return to where he was a few seconds earlier.
Levels 2 to 4 and the first scuttle: that's when Ekko's clear matters most. Track his path, invade while he's on a camp and pressure his side of the map before the first dragon.
As Ekko, expect Lee Sin to come into your jungle early: clear the camps near your lanes first and ask for help if you see him coming. Stand behind monsters so Sonic Wave hits something else, and fight inside your Parallel Convergence, not outside it. From level 5, Chronobreak gives you a second chance if he kicks you.

Favorable matchup
Reviewed for patch 7.3d
Ekko wins his fights with burst: he comes in with Phase Dive, stuns with Parallel Convergence and finishes with Timewinder. Warwick has the tools to take it. Primal Howl cuts the damage, his passive heals him at low health, and Blood Hunt tells him when Ekko runs away hurt.
Primal Howl reduces the damage you take for 2.5 seconds and, when it ends, makes nearby enemies flee. Activate it when Ekko jumps in with Phase Dive: you absorb part of the burst and the fear forces him away right when he wanted to finish you.
Below half health, Warwick's attacks heal him through Eternal Hunger, and Jaws of the Beast heals too. A burst that doesn't kill you outright leaves Ekko without his edge and with a long duel ahead of him.
Blood Hunt senses enemies below half health and gives you speed toward them. If Ekko leaves the fight hurt, you can follow; once he has used Chronobreak, Infinite Duress suppresses him and ends the fight.
In the first levels, look for fights in the jungle and at scuttle, where Ekko doesn't get to pick when he comes in. Later, let him jump on you and answer with Primal Howl: the long duel suits you.
From Ekko's side, don't open on Warwick while he's above half health with Primal Howl available: wait for him to spend it on a camp or another ally. Go for their marksman or mage before him. If he follows you with Blood Hunt, Chronobreak takes you back to where you were and heals part of what you took.

Execution matters
Reviewed for patch 7.3d
Ekko gets out of almost anything with Chronobreak. Vi has the answer for when he's already spent it: Cease and Desist runs him down even if he moves, knocks aside anyone in the way and launches him into the air. With Chronobreak up, though, your ultimate can come to nothing.
Cease and Desist runs down a champion, knocks aside anyone in the way and launches the target into the air on arrival. Phase Dive doesn't leave you behind: the ultimate follows its target.
Vault Breaker throws you forward and knocks back the enemy you hit, and Blast Shield protects you after stacking hits. Ekko wants to get in, burst and get out; you want the fight to last, and every knockback and every shield stretches it.
Denting Blows makes every third attack on the same enemy deal a percentage of their maximum health and lower their armor. With Ekko in the air after the ultimate, you have time to reach that third hit.
Look for Ekko once he has spent Chronobreak. Before level 5, gank with Vault Breaker and don't chase him blindly through his jungle.
Playing Ekko, don't spend Chronobreak on damage you could have avoided: against Vi it's your insurance against her ultimate. If she catches you, take the knock-up and use Chronobreak afterward. Before her level 5, fight inside your Parallel Convergence to stun her if she charges Vault Breaker.