Do you understand that his reflexes are Suigetsu level? Almost everyone on the list blitzes him. His chakra reserves are Kakashi level, the Rain absorbing Jutsu was used by a Biju Jinchuriki and Hidden mist is a fairly taxing Jutsu as well. His best offensive Jutsu here is a basic Suiton Jutsu. Early Part 1 Kakashi was able to maneuver around in Zabuzas hidden mist to an extent, even the weakest character here is
significantly above that version of Kakashi. Il break it down for you:
Round 1: Team Hebi consists of Jugo, Karin, Suigetsu and Sasuke. Karin is a sensor, which makes Hidden Mist useless. Jugo has tough skin and is filled with natural energy, Samehada is terrible against him. Mangetsu has nothing that can harm CS2 Sasuke and does not have the reaction speed to react to base Sasuke. Sasuke also has snakes, which see through heat signatures, thus the mist is pretty useless. Sasuke can easily solo, however having Karin here means he won't need CS or Snakes. Team Hebi No-Diff.
Round 2: Sasori. Mangetsu can probably pull off a win here, I will give him this one. Mangetsu High-Diff.
Round 3: Tsunade. Mangetsu definitely wins this one, I will give him this one. Mangetsu Easy-Mid Diff.
Round 4: Jiraiya Summons Gambunta, jumps high in the air out of the mists reach and fire multiple Water Bullets and/or Katon. Jiraiya summons Gambunta and uses his insane AoE Katon to fry Mangetsu. Jiraiya enters SM, senses Mangetsu, and obliterates him. Many possibilities here. Jiraiya Easy-Diff.
Round 5: Deidara simply flies out of its reach and bombards him with his bombs, that's even IC of him to do. Mangetsu lacks powerful long range Jutsu here. He can also just use hiding like a mole and outlast the mist. Deidara Easy-Mid Diff.
Round 6: Clone explosions are his best bet, if he can blitz towards him and land Genjutsu that would be good as well. Itachi is a bad match up here but he ultimately wins High-Diff.
Round 7: Ei blitzes him right off the bat. Mangetsu possesses no means of actually injuring Ei, he gets close a single Raiton swing ends him. He can't possibly win this. Ei wins Easy-Diff.
Round 8: Izanagi behind him, place the seal and GG. Baku sucks him up literally anything Mangetsu can throw offensively (including the mist and the absorbing rain). Danzō actually wins this No-Diff, Baku alone can probably solo lol.
Round 9: Ōnoki wins this hands down. Flys up high in the air and uses a massive Jinton. Uses a Golem to stay out of reach to outlast him. Uses a Doton fake to make Mangetsu extremely heavy. Ōnoki wins Easy-Diff.
Round 10: Hirudora soloes, even if it does not directly hit Mangetsu, it blows away everything (including Mangetsu and Gai finishes off the scraps with his 6th Gate flame punches. Gai Mid-Diff.
Round 11: Tobirama is a sensor who is extremely fast, he destroys Mangetsu with No-Diff.
Round 12: 360 Amaterasu GG. Mangetsu approaches he stuns him and finishes him off. Or blitzes him from the start. Sasuke wins Easy-Diff.
Round 13: Two ways to deal with this, spin around in circles or Bijudama the ground (He gets injured but not killed while Mangetsu gets killed). Spinning around in circles should do the trick though. Bee wins Easy-Diff.
Round 14: DSM Kabuto can beat him in 10+ different ways. DSM Kabuto wins No-Diff.