It’s The Final Countdown
Theoretically the remaining cultists could have alighted to the temple floor to continue the battle, but they knew what needed to be done and understood that their window of opportunity was over. That being the case, and because it was getting close to closing time, I opted to make it that the failed ritual feed back into the summoning loop, knocking them out of the air and frying their nervious systems. Severin had a particularly gruesome end: the Mask of the Dragon Mother that he wore for the ritual basically crushed his skull as punishment for his failure. The barbarian seemed hell-bent on not just picking up but wearing the Mask, which…I’m not sure what would have happened. Maybe he would have been possessed and taken the central apse to kickstart the ritual anew, but the party seemed willing to do whatever they could to stop him. In the end, though, I figured it would make sense that, understanding that the ritual attempt had failed, the mask would return to it’s relatively dormant state of five pieces until they could be embued with enough energy to again fuse into one mask to start the ritual again.