idk... I think the sect leader might have been too focused on himself, and the mc is someone who knows the future. Maybe in the original timeline, things weren't as clear as the mc make them be.
If the sect leader is too focus on himself as you claim it, then he is really not a great leader. I vividly remember that MC said that his father knows everything, if he knows then why he didn't reprimanded those who oppressed people? Even if the mc is from the future, he just know things like a particular person or people died but he really don't know the internal power trippings in their sect, that's why he is basically walking in the egg shell cause he also don't have any idea who is his ally or enemy.
The mc here is not really like the other regression who already knows something and I like it. It keeps me curious (⌒▽⌒)
I think the MC's father is not really a great leader. All of these happening under his eyes and he didn't even do anything before regression? The pedos, abuse, bullying, etc. I know there's more worst crime to see as the story progress.
Which makes me think the MC's thought, it something like are the fall of their sect is because of the hwang person. It made me immediately thought that the fall of their sect already happen before the attack because of the members within the sect. Oppression and Power tripping is heavy in their sect that I think they failed to strengthen or make themselves stronger to protect others.