Re: anyone recognize this mystery dungeon of darkness?
This game is hacked.
Mewtwo and Mew can never be partners, not overworld sprites at least. Further proof is that the letters can't choose whether to be uppercase of lowercase. Lastly is the fact about items.
Restart, and see if that clears up the issues. If not, return it to Gamestop and tell them the game was hacked and won't work properly.