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.
Oh, what if Magatsu asked uncle to take the sword back to earth and place it at someones ancient grave? Also, Sharion confirmed royalty. I wonder if they heard him mention who he got the spell from or if they'll just assume he's the real king?