Here is a developed concept feature (game design document) for a "True Boss Fight" scenario based on your prompt.
: The cartridges found in-game are believed to be the consciousness of previous players who failed to escape. mita miside giddora full
: The term may be a corrupted version of "Ghidorah" (the multi-headed kaiju), which is sometimes used as a nickname for "Crazy Mita" due to her multi-faceted or "multi-headed" personality shifts. Here is a developed concept feature (game design