>>55960055NTA, but the prison Advent were kept in was very famous in the Underworld, which makes it sound like that's where it's located. Maybe Mori strolled by while the girls were doing their escape and Mori pulled some anime chuuni lines like "Oh ho, you want freedom? Fight for it, then." And challenged them to a bit of cheeky sparring or she'd go sheriff mode and put them back in the slammer.
Nerissa is nerfed, Shiori plays her cards close to her chest so she doesn't seem to use her potential powers, and Fuwamoco are mainly physical fighters. So Bijou would be the natural choice to try and fight a powerful being like Mori. Did well enough to earn Mori's respect and get her to let them through.
This is all based on Mori and Bijou's latest Undertale stream, that was actual kino, would recommend.
