Dr. Strange: MOM was a Xianxia novel.

Demonic cultivator mc (Scarlet Witch).

Mc having complete knowledge of complex arrays traps and escaping when the thing they got him/her. (Scarlet witch literally doing that).

Sect: Kamar-Taj.

The shield array of the sect grounds (The array they made).

Disciples being wiped out left and right (useless).

The elders being killed with one blow (The masters of Kamar-Taj literally being killed with one blow).

The only ones having any chance against mc is the ancestor and even then they were defeated (Dr. Strange being former sorcerer supreme).

Sect gets totally destroyed by mc but not totally destroyed so they can enjoy misery. (Probably will need a lot of years to come back to its former glory). They were spared due to an trace of emotion for his former life in the sect.

The war started due to a brat (young master) offending mc. (Scarlet Witch Literally trying to get America Chavez to get to her children).

Mc could have rules over the whole continent but destroys sects and villages just due to emotional damage. (Scarlet Witch having the power to rule the multiverse but she just wants her children.)