Momo handles the ancestor much better than Seiko by using the old carrot and stick (and some blackmail 😅)
Thinking about it, Momo's deviousness is rather relatively cute/comical for the magical girl standard. With Lilith's long dark isolation, Shamiko being almost crushed as a child by the seal and the fact that demons used to be treated as xp stockpiles by several light clan members... Even the current Momo is angelical in comparison...
Dark side, er, aside, Shamiko says the outfit is embarrassing but it's a lot better than her combat outfit. Not simply that, I would say that goth lolita style suits her quite well.