A few things to note about Ekko's ultimate
Yes, it's powerful. But before you complain about how OP his ult is, I'd like you to realise a couple things about it.
- Ekko cannot choose where his ult takes him.
Ekko goes to where he was 4 seconds ago. If he hasn't moved, he stays where he is. In essence, this means that if you DIVE Ekko instead of him diving you, while he's simply stutter stepping around, his ult is not a "free escape." His ult is a free escape if and only if he is actively moving around the map, and even then, he doesn't have any choice at all where he's taken.
- Ekko generally either gets the damage or the escape, but not both.
Closely related to the first point, if Ekko dives in, does a combo, then ults out, he's not going to be hitting anybody with his 1.3 AP scaling on that ultimate. So take that completely out of the equation. Likewise, if Ekko is dived and his shadow is near himself, he's not going to be getting the escape at all, but he may pop you with the damage.
When WILL he hit you with his damage? Only if you dive him or you chase him. Ekko excels at kiting and counter-engaging on people who chase him, and those who are blind enough to stand right beside his shadow at any point in time probably deserve to take the damage anyway (Ekko walking into brush can be a tough story, though).
Now, I'm not saying everything is perfect and fine with his ultimate. We haven't had the time to really figure out what to adjust on Ekko. However, do realise that his ultimate isn't simply "a 1.3 AP scaling nuke that heals him and gets him out of any situation period," because that's simply untrue.