i've said this in a thread long ago, but i think my thoughts on it are still the same.
Sage is mostly balanced, she's a good pick on maps like bind, ascent, split, etc. The only thing I would change would be her self-heal to do 40 instead of 30. 30 is nothing and can't even save sage from an extra body shot if below 10 health, but 40 can give her that survivability while still being encouraged to use it on teammates instead.
Cypher I actually think is totally balanced, but it's just not his meta. I also think the camera cd should be lowered, but not by much, maybe 5 seconds at most.
I hate Chamber because i have PTSD from his prenerf form but the upcoming buff should make him a bit more usable.
I think KJ is balanced but the ultimate is too strong. You're either forced to save a brim/sova ult to counter it or literally play full retake. My nerf would be that the range of the ult be smaller so it doesn't cover literally all of a site for free, meaning that KJ would need to place it more aggressively to cover more ground, leaving her and the ult open to getting shot/utiled out more easily. It wouldn't be a super nerf, but just make the range slightly smaller, enough so there's that tradeoff