Can i get an explanation to what i'm supposed to do with the medallions? please...
There are three medallions in the mansion in total. To find the one you're missing, try one of the rooms on the west side of the mansion's top floor. Once you've got them all, you need to head down the stairs to the very bottom floor. Once you're there, you should see how you can use them. Good luck! (Don't worry about the pink fiend for now)