User blog comment:IamJakuhoRaikoben/Chapter 492: Elder Sister and Younger Sister, Review./@comment-4449950-20160705100735/@comment-7418318-20160706093749

And there's also Lisannas over-confidence in spite of all the evidence pointing to her being barely above fodder level. That has irked me ever since Tenroujima.

I just had a possible (though somewhat strechted) thought on how the Plutogrim Take-Over might have worked.

The theory is that Hell's core is a part of Cube/Plutogrim rather than being something seperate that just happened to be inside it. Imagine it like an inner organ of a bigger organism. Furthermore Alegria wasn't creating something, but just awakening Plutogrim from it's semi-dormant (Cube) form into it's fully active form.

When Mira used Take-Over on Hell's Core, it also connected her to the bigger being and thus she was able to siphon part of Plutogrim's dormant Alegria power off for herself.