@Nunally
I said this in another chapter, but this entire plot is rooted in maintaining a political image of a family. And an afair accusation where there isn't any proof whatsoever. That is it.
And that if any of these actions ever were made public knowledge, then the Angel Family's reputation would be destroyed irreparably. Sending assassins, causing immense property damage, directly interfeering with the lives of students who are not their own, killing school staff, etc... all for an in-house issue.
Remember that they are the ones meant to be the greatest family that protects the people? They sure don't as they are time and time again causing needless death and distruction all to keep something that no one outside of the family even knows a secret. And that secret may not even be real.
Either way her "father" clearly doesnt want her even if she turns out to be his actual daughter. So if it wasn't clearly a threat to he life, I actually would like her to jump on this opportunity to smear shit on the Angel family with the exception for her cousin. Just only if this new guy was a decent person who didn't just kill a bunch of people, than this could have been an amazing chance.
Side with the assassins, and secretly disclose the Angel family's involvment, placing the blame for everything on their family, which not only make her look like the victim of massive amounts of needless abuse, but then ties the Angel family hands because if they admit to it, they are done, but if they deny it, then that means she has to be their daughter, which means there was no reason to do any of what they did, and she will have to become a member of their family whether they like it or not.