Responses
Since it’s been moths I’ll answer that in case you dropped the story.
*SPOILER*
you need to be born from a witch to be able to bloom. Just wearing that necklace won’t do anything. The ‘empress’ had been spreading the witch’s seed amongst the population for a while so it had a lot potential witch that can then be bloomed either trough a traumatic experience or the ‘mother’ witch aka the empress.
Just my opinion...
At first we got confused why inase didn't know she is a witch. But then i think it was connected with the "bloom" . The necklace that the empress dowager gave to each and every fiance of the crown prince MAYBE is a tool to turn a human into a witch but it depends if the human's body can take the change or not .
Simply put it's either they turn to witch or go crazy or die ...