You stated nothing to resolve with this comment...
In your words for the second time now, "If a fictional character is stated to be 18 years old, they are 18 years old" You must clearly be ok with CANONICALLY underage children having sexual interactions because this ped*phile of a developer did nothing more then say they were 18 rather than, changing the appearance of the characters so degenerate ped*philes like you can miserably m*sterbate to this collection of child p*rnography.
Whether something fictional or not is put under a label, just because the label transcribes a subject into something different, doesn't mean it fully identifies under the label. In short, you can not take a picture of a child (fictional or not), call it 18, and use it as marketable p*rnography just because you decided it to be 18 years old.
It is illegal and is registered under child p*rnography...
CONSTITUTIONAL LAW:
Child pornography under federal law is defined as any visual depiction of sexually explicit conduct involving a minor (someone under 18 years of age). Visual depictions include photographs, videos, digital or computer-generated images indistinguishable from an actual minor, and images created, adapted, or modified, but appear to depict an identifiable, actual minor.
And WAIT there's more...
SIMULATED PORNOGRAPHY:
Simulated child pornography was made illegal with the Child Pornography Prevention Act of 1996 (CPPA). The CPPA was short-lived. In 2002, the Supreme Court of the United States in Ashcroft v. Free Speech Coalition held that the relevant portions of the CPPA were unconstitutional because they prevented lawful speech. Referring to Ferber, the court stated that "the CPPA prohibits speech that records no crime and creates no victims by its production. Virtual child pornography is 'intrinsically related' to the sexual abuse of children".
You've lost.