Since the fall of the mysterious man, Death Eaters have been imprisoned one after another. The daughters of Death Eaters and those who were framed are trying to survive under the neglect of their grandfather who hates Death Eaters...
It's quite Mary Sue, the heroine doesn't travel through time or is reborn.
There may be some overlap with some stories (I hope not). The background of the heroine is the same as that of Miss Black's Hai. (Wonderful article)
CP is quite funny, Snape × original heroine (daughter of Sirius)
Purpose: A member of a crazy family