Ekko is a champ who can be played at many levels you can carry games just with your w or by going full tank and taking out the back line.
There is no harder carry than ekko even with the nerfs with this build path and I will explain why below.
Why these items
1. Sunfire- this item is pretty common for him now and its good overall.
2. Executioners calling- This might come to shock you as why but against champs like maokai or attrox its supper effective and can decide your lane.
Triforce- With the new changes and how the sheen is 2x strong than the sheen in iceborn why not go tri. IT procs amazing with ekkos passive for the 3rd auto or ability the bonus damage is insane even when your ap you still get a couple hunred ad in there so theres nothing wrong.
Rylais- Helps you stick onto your target like iceborn did but its pointless becuse you already have sheen.
QSS- Its pretty standard if the enemy has a lot of cc.