So any guesses as to who the next Supreme is?
Here's my guess. I have a feeling it may be Nan since she was with Madison when the curtains spontaneously combusted. Madison said she didn't know she could do that, perhaps
she didn't and Nan never let on she was the one who did. Similarly Madison is uncertain if she was responsible for compelling the pedestrian to walk hap-hazardously into the street. When Madison questioned Fiona which of them was controlling the pedestrian, Fiona smiled but never replied.
Nan was also the one who alerted the council to Madison's missing thoughts which brought them to the school without informing either Cordelia or Fiona why when they both were there at the time. The question of what happened to Madison quickly derailed into the council putting Fiona on trial for her failure as the current Supreme. I think Nan may have known the contempt that Myrtle and the council had for Fiona and used it to Maneuver Fiona out of her way.