Is one in a state of major ritual impurity (junub) impure? Does sleeping in a state of major ritual impurity harm a person, such as exposing them to demonic possession (mass)? Does touching the buttocks invalidate ablution (wudu')? How does one in a state of major ritual impurity perform ghusl while retaining their ablution?

It is permissible to sleep while in a state of major ritual impurity (janabah), though sleeping in a state of complete purity is better. One should not abandon the remembrance (dhikr) before sleep. If a person in a state of janabah wishes to maintain their ablution (wudu') after ghusl (ritual bath), they should perform ghusl with the intention of purifying themselves from janabah, then say "Bismillah," wash their hands three times, then wash the area of impurity, the private parts, and the anus. Then, perform ablution as for prayer, without touching the penis or anus after washing them, while intending to remove the minor ritual impurity from the hands when washing them after the face. Finally, pour water over the entire body and head. Merely touching the buttocks does not invalidate ablution, but touching the anal sphincter does.