That went ok, but someone who, coincidentally, had the right power for the job, had to sacrifice themselves unfortunately.
Mind you, I've seen "coincidences" even with popular manga so I can't exactly complain about that... much.
Now, just waiting for Kinjo or some other witch to do something. Empress is pretty much the biggest (known) villain after Kinjo, but if somehow other witches felt the Empress' death echoing throughout the world, maybe a power vacuum or something will happen? Orrrr Nishina is actually evil, who knows.