I really wish the red hair daddy would explain to the ml what really happened to his parents (cause let’s be honest he prob didnt really kill them) or if he did then... THERE MUST BE A REASON
What I think that he didn't kill but instead he might have come to save them but he too late but when ML opened the door he saw wrong or has been late as the people who might had killed his parents would have already fled or killed by daddy so daddy brought him to the demonic sect to protect him as he had said all the people who are near him ended up dying.
Since im still a student and broke, i bought 2 chapters to support the author (ಥ﹏ಥ) i hope that helped