Is there a word that refers to or describes the subset of neologisms derived specifically from the names of fictional characters?
If you can handle two words: we might describe such terms as literary eponyms.
From Daily Writing Tips:
3. Literary Eponyms
Fictional characters often evoke such strong qualities that we assign their names to those qualities: faustian, quixotic. We also refer to people who exhibit qualities of literary characters by directly associating them, such as when we call someone a Casanova, a Romeo, or a Svengali (retaining initial capitalization), but some other such terms, such as lothario, are lowercased.