207th Brawl: Game froze mid-attack

This is a known issue related to secrets originating from Shifting Scroll or Chameleos. See Known Issues List 2019 - Updated Dec 12th - #8 by Aelathera (May 22 update).

The best you can do when this happens for now is to quickly force-quit the game (Alt-F4), restart, and then it should be fixed when you reconnect.