Zelda fears for Prudence and the other disenters as they are on their own in there against Blackwood and his Judas Boys. Sabrina kills the Mandrake Sabrina and Ambrose meet with the mandrake.

Does Sabrina get her powers back after killing the mandrake?

Lilith becomes Queen of Hell and takes him back where he belongs, but not before she restores Sabrina's powers which had been sorely absent since the mandrake absorbed them. This effectively gets her back into fighting form to face what awaits her in Part 3…

Does Sabrina go through with the mandrake spell?

Unfortunately, the mandrake spell did work and created a double of Sabrina that had her powers. She visited Sabrina's friends and tried to make mandrake versions of them. Dorothea's ghost woke Theo, who smashed the mandrakes and woke Harvey and Roz.