The explosion from the Scarlet Mistress' explosion sent Kai Syaoran flying backwards but he was powerful enough to prevent any damage to himself by using a well-placed barrier that deflected the powerful force around his body.
When everything settled down, there was nothing left of the Scarlet Mistress.
Everyone was shaken to see the death of a genius so unexpectedly. Just a few minutes ago, she had been discussing important matters of war with them and she was now dead with not even a corpse left behind for her burial. This once again reminded people that life was short. Even cultivators with the potential to live for millions of years were not spared from death. This was simply the fate of all the living.