Ekko is a great fighter with ranged abilities. He is great at harassing the enemy so keep them pushed back until level 3 when you can start to produce some effective combos to finish them off.

Ekko is best as a solo lane champion. You should always aim to place Ekko in the mid lane but if your team disagree you can go top the only downfall being if there are 2 enemy champions at top you will probably have to build defensive and rely a lot more on ganks.

Ekko MUST be on his own in lane as his items are expensive and he only becomes super effective once LVL 4 eventhough if there is a low health enemy champion you can still do damage at LVL 2.

Early game take advantage of Timewinder to harass the enemy and keep them stuck near their turret. Also when they are low enough utilise phase dive to go in for the kill.

Mid game continue to harass the enemy but if your team are being to fall back support them as much as you can and make sure you build health as Ekko is a weak champion. Whereas if your team are stronger than the enemy continue to push them back and make sure you stack up your ability power.

Late game focus on getting the kills. Even when your enemy are on half health a quick attack can be devastating as long you have built him correctly

Chronbreak is super useful if used right. It can help get the final kill inside a turret then use it to quickly get out of there or if you need to get out of team fights quickly

Just remember the time clone is 4 seconds behind so don't stay in prolonged fights as if you need to get out even chronbreak needs to be far enough away so with the healing done Ekko can still take some damage

Late game Ekko can work really well with strong supports that can stun and slow enemy on top of his stuns and slows so Ekko can move in and get the kill.