Oh boy... you're in for a treat.
Are you talking about the convocation of mirrors event because if so I know their origin. IMO what they did before they were gods is less important than how they are currently using their powers. If they maintain or use that power in unethical ways then that is more like what I am talking about. IRL those in power torture and murder for meagre profits.
Also a secret that they would want expunged would be something that could threaten them or their positions like a weapon that could kill them. IRL those in power don't tolerate any threats. Security systems are built with zero trust, we live in a surveillance state, and all potential threats are neutralized even if no crime has taken place.
This is why bravery is a necessary quality in those who have power. It prevents cowards from overreacting because they fear something might happen. They also won't kill or torture just because someone else tells them to.