This guide was originally for top lee sin. However i realised lee sin can be an amazing 1v1 dueler but he works well with another teammate. playing lee in the jungle allows you to gank early and allow known OP champs in low elo like amumu to get through. This is because lee crushes most junglers in mobility and in early level jungling, 1v1 fights. People will always are open to lee sin ganks ( even more when he has wriggles when he has the ward to dish out. He is THE carry for early and then becomes a more assisting fighter in action in late game while still dealing a lot of damage.

Pros
Great sustain
Early game damage is insane
Good lane harass
Wins most lane encounters
Ulti changes fights
works well in ganks

Cons
Has to be in melee range
vulnerable to cc
late game can lack
works well only solo roles
Cannot take a lot of punishment