"noah yoｕ suck" You can unlock this boss fight by finding the secret passage to the Power Station in Act 5 of the Backrooms. What you'll want to do is make sure when you get to the Power Station that you have the Comb of Evil and Doom and the Brown Lip Filler. This allows you to summon Mean "MNL" from his chamber. In reality, Mean MNL is just a recolored LNM to look like MNL. The reason why is that the developers rushed when making this segment, as it was suggested 2 weeks before the game would release on 4/20/2017. Here's a tip to defeating him: you want to attack him when he's charging up an insult. This will cause him to spit out his mean words early, and this allows you to hit him multiple times until he snaps out of it. He will then roar at you, pushing you away from him. Rinse and repeat until Mean "MNL" dies. When you defeat him, you get the MEAN SWORD, which gives you 9999 Attack Power. I recommend you use Noah for this boss fight, as he has a (Its_Me_)passive 20% damage buff towards this boss in particular. I wonder why...
(fost stands for fake official soundtrack because there is no mnl and the secret rings) @noahsaturn for his character or something
