League of Legends (LoL) Question: Best banns when playing Lee Sin MID?

I would personally ban Cassiopeia, as her Miasma prevents Lee Sin from using his main abilities, Neeko, as she can burst you through minions, and even if you get close she can Flash+ Tangle-Barbs to peel herself and chunk you, and probably Galio as the last one. Galio is just way too tanky to do much to him, and he does quite the bit of damage early game. Winds of War prevent you from walking up to CS without taking poke. Hope I helped.

I played Lee Sin mid lane to get my mastery 7. Lee Sin is actually really powerful in lane against most matchups. However anything that can lock him down easily will ruin him. Champions like Lissandra, Pantheon, or Cassiopeia should be banned.

Tbh, all of them, lee is not very good as a midlaner. But the most important would be Corki, Diana or Tristana, if you want to be able to play the game.