okay this is all i remember;i am sure its a bl novel , mayby quick transmigration , in this arc i think that the mc is a ger princess from another country .the ml is royalty . there is an official whos daughter is ml concubine and he is planing to rebel . i think the ml left for the battlefield when he married to orihost , so the orihost was bullied and poisoned by ml concubine then the mc took over . also there is a scheme by the concubine and her father to frame mc of adultery with orihost brother but the ml and mc brother knew what they were doing so they played along but when they caugh them in the act it wasnt mc and another man it was mc and ml . sorry if this is all over the place
i know , i just found it , it wasnt on novelupdate reading list which is why i didnt find it , it was in my library on webnovel its caled love system changing destinies on wednovel if you are interested.