Under a principled reading of copyright, a character's style or appearance should not be protected at all. The Constitution authorizes exclusivity only as a means "to promote the Progress of Science and useful Arts," not to fence off cultural building blocks. Characters are ideas clothed in minimal expression, and ideas are supposed to remain free. Extending it to style or appearance criminalizes inspiration and imitation, both vital to the creative progress.
There is also no need for copyright to protect style when trademark law already handles the commercial side. Trademark law exists to prevent consumer confusion about the source of goods or entertainment, not to police creativity. Copyright, by contrast, exists to encourage the creation of new works. Mixing the two systems produces the worst outcome: censorship of reinterpretation with no public benefit. By allowing registration of character depictions, Congress and the Copyright Office has quietly transformed the protection of expression into the protection of concept, eroding the barrier between idea and form that once defined the system's fairness. Forbidding others to write new versions of Harry Potter or Sherlock Holmes stifles cultural dialogue. This kind of control limits creativity and weakens the public domain. Copyright law was meant to protect expression, not to freeze imagination. Limiting the reuse of character archetypes harms artistic development and public participation in culture.
If someone wishes to write about a wizard boy, a detective, or a talking mouse, they should be free to do so provided they do not mislead consumers through trademark misuse or copy the exact material. That balance preserves both artistic freedom and commercial clarity. Characters are part of the shared language of culture, and language must remain free for all.