From Bulbapedia, the community-driven Pokémon encyclopedia.
Main Street Colosseum (Japanese: ストリートコロシアム Street Colosseum) is the second Colosseum in Pokémon Battle Revolution. The battle theme is knockout battles. The Colosseum leader is Colosseum Leader Taylor. Like most other Colosseums, there are 7 battles in all.
Main Street Colosseum is located in the middle of the main street in Pokétopia, Main Street. Battles here are always depicted as being in the daytime (Most likely the morning). It is on a raised platform in the middle of the street, and has two huge balloons floating on one side, a Pachirisu balloon and a Bidoof balloon. The surrounding buildings, which all are circular and have the Pokétopia logo on them, all have second-floor balconies, with regular balloons tied to the railings. Fans and tourists, eager to watch the battles, always crowd this balcony.
After you beat the game, you are allowed to utilize the Level 50 All rule.
Beating Main Street Colosseum for the first time in Level 30 Open mode gets you a Pikachu Badge, a custom Battle Pass with Main Street Colosseum in the background, and 325 Poké Coupons. It also unlocks 11 pieces of gear in the shop. Beating Main Street Colosseum for the first time in Level 50 All mode unlocks 24 pieces of gear in the shop. Also, when you beat Taylor, you will recieve the outfit she is wearing, which will either be a regular Pachirisu costume or a shiny Pachirisu costume. The chances of her wearing a shiny Pachirisu costume is very rare, however.
The default mode of battle here is Single Battle. An option to change this to Double Battle is made available after beating Rank 1 for the first time.
The Pokémon and Trainers are not set, except during the first time you battle there, at Rank 1 Level 30 Open, and the first time you battle there using the Level 50 All rule, Rank 1 Level 50 All. The Trainers, and the Pokémon they have, go as the following during Rank 1: