What the Lord Ruler does for mankind
On a reread of the original trilogy, and I was thinking about what we know about the Lord Ruler's normal activities. Constant emotional soothing.
I think that his intention is to sooth Ruin in it's prison so it does not act as much as it would if it had more freedom of emotion.
But I was also thinking about Copper clouds and how TLR knows much more about Allomancy and Investiture in general.
I think he can shift the frequency he obscures, and was probably constantly copper clouding on a different frequency, Ruins frequency. This way he was also constantly stopping Ruins power from spreading out far and wide, or letting it's senses get far out into the world and affect things on a large scale.