What I was thinking with this is -
The House is a human house. It was built in the human world to shelter humans. It loves its occupants - those who hide in its nooks and crannies, those who so carefully wash its floorboards, those who dance and cry and sleep inside its walls, trusting the House to keep them safe.
And then something unimaginable happens - a threat comes from inside. The House has strong, sturdy walls. Its doors securely lock and are made of the finest oak. Its windows are fitted sensibly and close tight. The House can keep out any manner of threat, but this time it was not given that chance.
And then it is dragged to hell.
Dismantled brick by brick, stone by stone, reassembled in a place where the sun never shines on its old paint. Has it absorbed anything of human religion while it had them living beneath its roof? Does it think it has done something wrong, to have let a threat inside and failed in its duty as a House?
Demons take up residence and it’s… fine. Satan reads on the same windowsill Theo did centuries before. The scent of roses seep into its walls in Asmo’s room. Other things seep between the kitchen tiles - Beel can be a messy eater, and enjoys his meat much bloodier than the House can recall any previous occupant doing, but little Jeremy used to push whole plates onto the floor.
Changes are made to it. Lucifer strengthens the House’s exterior so it can stand up to the strange, violent weather of the Devildom. The basement is expanded beyond what the House had thought possible and made a tomb. A room is made in an impossible space, hidden from view.
Lucifer completes his paperwork in the same study a dozen other family patriarchs had. Levi takes shelter from the cruelty of the outside world in his room. Mammon runs through his halls with the energy it has witnessed from generations of children.
They are not bad occupants, overall. Damage - and there is often damage - is swiftly repaired. It is kept sensibly clean by a rotating chart of the brothers, one enforced by Lucifer with an iron fist. The brothers live and feed and sleep within the House. But they are not human, and the House misses humans.
Then you come along. The House does not understand days, weeks, months. Only that you have slept in your bed for longer than a usual guest, that your closet is full, that you study and eat and laugh in its walls.
The changes are subtle so as not to be noticed.
Beel complains he keeps stubbing his toes on the main stairs now. Mammon nearly falls more than once. But to you, they are perfect - the most comfortable height for your legs.
There are no corners where shadows collect in your room - no places for nightmares to hide, waiting for you to sleep. There may be no sunlight, but your room is a bright space in the rest of the dreary House.
You never got lost, despite the House being so large and unfamiliar. There is always some shadowed space to avoid Lucifer in. It even opens up the secret room to you and Beel when you have need of it.
When you are killed, the House mourns - when you return, it rejoices. The fires on the stove burn enthusiastically, heating your favourite food (Satan has to take it off quickly, lest it burn). A small collection of library books push themselves out from the shelves, books from the human world you may like. When you shiver in your bed, the House moves warm water through the pipes to better keep you cozy.
Once more, a threat had come from inside the House, but this time it had been given a second chance.
When you leave at the end of the year, the House despairs even more than the brothers. It, after all, has no concept of why. It does not understand exchange programs or calendar years or your life beyond its walls. All it can do is wait, and keep your room neat until you return.
