what if, when Jack and Maddie built the portal they didn't take into account the possibility of there being more then just one dimension. Accidentally locking both of their kids down in the lab, what if instead of it just opening a hole into the ghost dimension it also tore a hole into a dimension that holds something more dangerous than ghosts. This is if the portal the Fentons had built tore accessed two different dimensions, the ghost dimension and a sub-dimension called 'Mementos'. I do not own Danny Phantom (Belongs to Butch Hartman) or Persona 5 (owned by ATLUS). (This description is a work in progress)