Which Mario Party game introduced the 'Bowser Party' mode for 5 players?

Mario Party 10 introduced the Bowser Party mode for five players. Released for the Wii U in 2015, the mode puts four players on Team Mario against a fifth player who controls Bowser using the Wii U GamePad.

The four Mario-side players travel together through a board while trying to reach the goal without losing all their hearts. The Bowser player pursues them from behind, rolls four dice, and uses the GamePad to trigger attacks and special minigames when Bowser catches up. This asymmetric five-player setup was designed around the Wii U’s two-screen hardware.

Bowser Party was one of two major modes added in Mario Party 10, alongside Amiibo Party. It should not be confused with the standard Mario Party mode, where four players travel together in a vehicle and compete to collect Mini Stars. Mario Party 9 had introduced the shared vehicle format, but it did not contain the five-player Bowser-versus-Mario structure.