Was that just the big sis being a huge Bocchi simp like usual or was she being genuine in thinking Bocchi should be triple digits? Maybe if they revealed Bocchi is Guitar Hero she could hit 4 digits.
The exorcism is meant to remove an evil spirit but what if Magatsu isnt judged as evil. The spell will end and they'll just be there looking at each other with Magatsu getting embarrassed at failing to leave him on the cliffhanger forever.