That's stupid. You don't need to kill her in public and some big spectacle. Just parade around the body to do... whatever it is you're trying to accomplish. This is literally the only actual chance you'd have gotten to actually kill the saint and ya'll gave it up for clout? That's just bad villianing. Seriously, the main characters went to the dungeon for seemingly no reason, exhausted themselves, AND nearly got themselves killed caving in the dungeon. It would've been so easy to take them down with the two of the bad guys and then just float in air and shout really loudly that you killed the saint. Boom. Done. Jesus and on top of not killing her the one that saved them gave the MC advice for controlling his magic.