If someone is mentally ill, the sacraments can only do so much.
There are a few malignant narcissists that I know about that attend traditional chapels. They never ever admit they are at fault for anything, even when it is proven they clearly are - it's always someone else's fault. If they ask for your help incessantly and you start to turn them down, they will say you are uncharitable and mean. If they ask for your honest opinion about something and the opinion is not to their liking, they will say you are hateful and judgmental.
I could go on, but you get the picture. For the most part, they appear exceedingly pious, but it's all a facade. Which is why we should never judge a book by its cover.
How could someone raised in a traditional chapel, attend traditional schools for twelve years, turn out to prey on little boys? I don't know, but it happened.
Catholicism isn't for the perfect. Our Lord said that the healthy have no need of a physician, but the sick do.