The guardian is a character found in Mario & Luigi: Bowser's Inside Story. It initially appears as a Napse-like being tending to the computer-like interface of the Memory Banks. The being has a blue body with yellow eyes and a mouth with yellow lips and blue thunderbolt-esque appendages protruding from their body (which seem to serve no purpose). When Mario and Luigi arrive to restore Bowser's memory so he can get the second Star Cure, it scans them and Starlow and determines that they are "viruses", transforming into digital, pixelated copies of the Mario Bros. known as Bowser Memory ML to repel them. After being defeated, it briefly transforms into a form resembling Princess Peach, explaining that it is a temporary observation protocol based on Bowser's most carefully preserved memory in order to aid communication between it and Mario, Luigi and Starlow. When Starlow asks for the safe combination, it then changes back to its original spherical form and goes through the library-like books of memory, pulling out both a memory of steak and Peach before finding the broken memory of the safe combination. The guardian reveals that Bowser's memory of the safe combination was shattered due to large-scale trauma, likely when Bowser was rammed by the Fawful Express prior to his fight.
In order to put the memory back together, Mario, Luigi and Starlow must piece it back like a puzzle. The end result is the safe number (9898-88241-983), which it puts back into Bowser's memory bank. Instantly, Bowser remembers the combination, and hums the song he used to remember it as he opens the safe. Inside the safe is where he obtains the second Star Cure, before being subsequently trapped in the safe by the Elite Trio.
In the original Nintendo DS version, the guardian can be seen any time later in the game in the Memory Banks, but cannot be interacted with whatsoever. In the Nintendo 3DS remake, Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey, it is not seen again after revisiting the room where it was fought as Bowser Memory ML.
- Browne, Catherine. Mario & Luigi: Bowser's Inside Story PRIMA Official Game Guide. Page 107. "The guardian of the terminal scans Mario and Luigi as they enter and determines that they are a threat to the system."[...]"As soon as the battle ends, the guardian relents and seeks out the memory of the safe combination."