[people have certainly seen glimpses of Lupin's outfit before, every time he summons a Persona: black jacket, red gloves, and white mask. but this time, he is wearing it from the get go!]

[. . . and also yelling out a brief explanation]

If everything looks confusing, it's because we're inside this guy's heart! It's just a representation of his distorted desires-- nothing in here is real!

Your goal should be that treasure chest behind him--

[oops no more instructions, he has to backflip out of the way of a splash of gold]