In Super Bomberman R, memory cartridges are possessed by robotic lifeforms that contain special ability data. As explained by Vic Viper Bomber, each of the Bomberman Brothers, having been created from the Prototype Bomber, can utilize one memory cartridge at a time by inserting it into their belt buckle. This feature is exclusive to the Grand Prix Battle Mode.
When selecting a Bomberman Brother, before selecting an [], there is an option to choose the memory cartridge of any other purchased character outside of the 8 Bomberman Brothers (the siblings do not have cartridges of their own) and MAX. If a memory cartridge is selected, the player character will gain the special ability of that cartridge's owner, and their stats will change to the cartridge owner's stats. This allows players to play as the Bomberman Brothers while customizing the characters to suit their gameplay preferences.
Simon Belmont Bomber holding his memory cartridge.
White holding the Belmont Bomber memory cartridge.
White attacks Dracula Bomber with his newfound power.