EKKO'S ULT

Posting this again since riot took it down.

So judging by the video I'm guessing his ult work similarly to Zed's. Only instead of leaving a shadow that copies his abilities he leaves some sort of marker that he can "rewind" back to a couple times after he hits R initially. I don't really see his ult affecting other champions except maybe he can choose a champion to reset along with him. How do you guys think his ult will work?