Tsugikuni (demons)

The tsugikuni twins but as demons!! Kokushibo(michikatsu): 480 years old(demon age), very protective of his little twin brother, obeys muzan, a bit of a father figure to the demons Yoriichi(or you can call him demon yoriichi): 479 years old(demon), protective of his older twin brother, broke free from muzan's control but obeys anyways, adopted rui as his son, very empathetic