WinterTimeCrime
It's a bit hard to explain without spoiling. đ Saori is in possession of a Pact Scroll (as previewed in Ch. 43) that're tools that enable the user to perform spells without magic (as explained in Ch. 52). With her new found power, one of the side effects is that she's slowly losing the ability to speak (in fact you can see that she can't talk at all now). They'll go over Pacts more in the next few chapters and the Revelations Arc so don't worry if you're still confused. đ Hope this helps! đ đ đ