Lee Sin balance idea taken from another thread
what if we gave lee sin players the vision that Rek Sai has when burrowed? Except they aren't revealed to allies.
Meaning he doesn't know who the champions are, but he doesn't need sight to see them, they can be in fog of war (Within reason, no more than normal champ range, vision wards would provide the same vision
If he hits an enemy with Q or E, they are revealed and he knows who the target is.
This way it makes up for how lee sin can commit and get off scott free, now he REALLY has to commit, not knowing who he is going after means he needs to be fully confident he can do something, or blow a lot of cooldowns to get out.
I would be ABSOLUTELY happy with his kit if this was the state.
There would be a few kinks to work out, but this actually seems like a good idea.