magenta seems to be some sort of mirror of enorme/imitatio.
>leader of their respective group
>got screwed with by basier to hard
>second form is not what they desired, but what was done to them by her
>both are broken out of their childishness by it, enorme from being a chuuni, magenta from the 'dumb clueless/asexual protagonist' syndrome
enorme's true form became the trauma she got after the severe spanking and infantilization. magenta's became the lewdness that was transferred into her when ugly flower of lust appeared, with the earliest manifestation of the changes being in chapter 44, when she was healing the other two in her base form and it gave them near orgasm, with sulfur commenting it's different than before.