@Enzeru:
No, no he didn't. Where did you acquire that piece of information (which chapter)?
Edit: Hundred Gauntlets stopped All Fiction's deterioration but it didn't become the skill itself.
My understanding is it went like this,
Kumagawa has book maker
Kumagawa trades book maker for hundred gauntlets
Kumagawa modified/changed hundred gauntlets to all fiction
Kumagawa traded hundred gauntlets back for book maker, as all fiction was based on hundred gauntlets, belived to have lost all fiction as well.
Kumagawa somehow manges to scrape the remnants of all fiction back together to create his deteriorated version of all fiction, as all fictions parts that were created from hundred gauntlets were not traded back when he traded for book maker, as they belonged to Kumagawa
Kumagawa recieved the inheritance and merges all fiction with unskilled to create april fiction.
So Kumagawa currently has
All fiction - full powered version - Maybe.
Book Maker
Unskilled
April fiction