So this is more brainstorming than an actual suggestion because I'm pretty sure Riot will never do it to Lee himself, but it is interesting to think about, and might be interesting to explore for a new champion concept.
Imagine if Lee Sin was permenantly like Rek'sai is when underground. He can detect moving champions, even through walls, but can't identify them unless an allied unit is nearby. However, his abilities that normally grant vision of an enemy would let him see them.
His Sonic Wave could be made bigger, so it looks like a sound wave. Also his cooldowns would be shorter.
Maybe he could have a passive that lets him dodge one skillshot automatically, and an ability that could be used for escapes. Or he could gain vision of an enemy when they used an offensive ability, similar to visibility of enemies in bushes.
Is there any way to make such a champion viable?