NOTE: This guide will be turned into a more fleshed out guide as I play more games and can fill out the synergies and threats. I will also add an entire written section as well.

MORE DETAILS

I have found so far that most Mundo Mid matchups are even or winning.

• If you play it right, poke matchups shouldn't be a problem. Having D Shield + Second Wind + Passive sustain means that you will die very rarely in these matchups. Also being able to poke back with Q + Comet + Scorch, you actually often out poke them and can get free kills with Ghost and Ult.
  

• The hardest matchups are champions that are really strong early game. The early game is when Mundo is at his weakest, but in Midlane you can usually survive by playing safe and last hitting with Q, even in tougher matchups.

This is an advantage that I think Mundo Mid has over Mundo Top. Not having to worry about being run down in the longer lane and bullied early, means that you can almost negate the weakest time of the game for Mundo. Since Mundo scales so well, surviving lane is super important and can usually set you up to carry the game.