Lee Sin is so extremely overpowered that he can penta kill in base without taking any damage at all. You will just need Safeguard/Iron Will to do that.
Here's a little tip: if u press Alt + F4 in game your smite spell can deal damage to enemy champion too, that' why double smite.
He need mana because he has just 200, that's why this build.
Special thanks to user Vitinho Maia who helped with this build.