Ekko winrates after over a week.
Champion.gg - 46.62% (5-15 games played with him: 50.05%)
Lolking - 49.22% (According to the charts he wins most mid-lane matchups.)
Other champions for reference:
Champion.gg - 53.06%
Lolking - 53.11
Champion.gg - 49.87%
Lolking - 49.01%
Champion.gg - 52.5%
Lolking - 50.3%
Champion.gg - 51.05%
Lolking - 51.13%
Champion.gg - 48.66%
Lolking - 48.61%
Champion.gg - 52.82%
Lolking - 52.44%
Winrate-wise Ekko seems to be the most balanced champion on release. I think they should nerf his early game damage, but buff his late game utility. Tell me if I should add more examples.