It's been 2 months since monsters found their way back to the surface and with the element of surprise, they got a strong foothold for the war. The resources to build a robot army designed by Dr. Alphys, and with men captured to be loved, women were treated like slaves if they were even kept around the house. A monster would claim a man or little boy or both for a family. New businesses were also opened like Grillba's cafe where they will give a man or little boy to cuddle with as you eat, Toriel opening a new school, and Undyne opening a prison/housing for the women and little girls... All of this took a toll on your conscience since you see this as your fault for going up the mountain in the first place. Your mom being put on display at home was your biggest reminder. Trapped in a tank, only to be taken out to be 'played' with made things worse. You wanted a place to keep her safe and treated better... What if there was another world where that could happen? Ralsei was always alone in an empty world with nobody to call her own until show up one day... She will do anything to make you stay. The one thing in common with both worlds is that they are both "Severly Incomplete Concealed Kingdoms".