Grand Colosseum is a special location within the Party Realm. It serves as a major hub area, connecting the Oni Realm and Celestial Domain.

The Grand Colosseum is a massive landmark located on a floating island above the clouds, positioned between the Oni Realm and the Celestial Domain, with floating pillars around it representing both areas. The island acts as a junction point between these two realms and is visually similar to the Colosseum from the First and Second Seas.

This area contains most common NPCs, including fighting style teachers, miscellaneous NPCs such as Nerd, Titles Specialist, and Tort, as well as shop NPCs like Plokster and the Blox Fruit Dealer. Most importantly, it houses the Party Gacha.

Inside the island is a central arena where players can participate in free-for-all PvP with no gains or losses. Outside the arena, PvP is disabled. The interior is decorated with colorful assets, giving the entire area a festive celebration theme.

Trading Tables are located on the left side of the main spawn area. Players can also join Ranked 2v2 PvP matches by stepping on matchmaking plates near the trading area.