The Gauntlet is a mini-game in Mario & Luigi: Bowser's Inside Story.
The Gauntlet is located at the bottom of the Challenge Node.
The Gauntlet is a mini-game in which you have to fight previous bosses but however there are X versions in which they have more HP, their attacks are more powerful, and some attacks have a higher attack count(like 3 orbs to 6).
There is also a turn count in which you must defeat the boss in that amount of turns or less.
There are a total of 7 classes you fight in The Gauntlet
Class 1: Durmite X
Class 2: Kretin X
Class 3: Wisdurm X
Class 4: Bowser Memory MLX
Class 5: Junker X
Class 6: Dark Star X