Board Thread:General Discussion/@comment-121.54.32.103-20130408082624/@comment-8638112-20130425084417

The theory of the two pairs of scissors is indeed interesting (since they were before the Twin Swords of Levianta, it seems logical that they later became, thanks to Chartette reforging them, two others "weapons" (each one becoming a pair of scissors)). This being said, there are two cutting parts in a pair of scissors, so Mothy could have thought that each blade could just replace the former Twin Swords.

An other point is that Ma could just, with her power, like "control" the Demon of Envy to keep him sleeping. We saw after Twillight Prank that Elluka could remove the Demon of Gluttony from little Rilliane, wich induce some strong magical power (even if it was to the cost of the little girl's memories). Since Elluka and Irina are reunited, we can assume she is now, at least, two times more powerful than before, and so she could have gained the capacity to refrain the influence the vessel (and the Demon) could have on her, that way keeping her mind clear to achieve her goal, and not turning into a awakened vessel controlled by sin.