I have actually done some Dragon Maid RPs before, most of them starting off with Tohru treating Kobayashi as a baby, as well as a couple with Lucoa being Souta's diapered plaything.
As for the one around 34Quacker's art, I am definitely on board with that. I have been a fan of his work for the longest time, in particular these pieces:
https://www.deviantart.com/34qucker/...felt-893729594
https://www.deviantart.com/34qucker/...ight-881313112
https://www.deviantart.com/34qucker/...cess-875309945
The guardian angel one definitely has potential, as well, but one of the first two would strike my fancy more at this time.