The Masked Mutant impersonates Libby for a long time. And if you look closely at the picture of him on the cover you'll notice that a part of his costume subtly resembles pigtails... Just like the kind a young girl would wear her hair in.
At one point in the book Skipper visits Libby's house, where she shows him her own comic collection. But if "Libby" is just the Mutant in disguise, how can she have a house and possessions? What if the Mutant did something to the real Libby?
Or what if anyone living there is childless and are forced to pretend to be Libby's parent(s)?
The Masked Mutant poses as a human girl and entrusts the Molecule Man with watching over his lair disguised as him. Except Molecule Man apparently isn't aware of his master's civilian identity as he tries to attack Libby before "she" kills him. Given the Masked Mutant's flair for theatrics and Medium Awareness, he was most likely setting his minion up to die as part of his "big reveal" when confronting Skipper.
The Masked Mutant cannot change into liquid since he'll be stuck in that form. How does he know it would exactly? Did he nearly tried to become liquid before and immediately realize it's fatal? Or was he told by someone who presumably gave him his powers?
