My interest in the manga considerably lowered after we learned that this bitch killed the targets of MC's revenge (the whole point of the story was for some sweet cold revenge, but instead we get nothing).
Then she also dared to kill best girl (for no apparent reason). Everything she does makes this manga worse. The only way for this to have a satisfying closure is for her to have a filthy death. Otherwise there's no point to all the edginess we have been through.