Death Note: Armageddon

Received 3rd place in the general category in the 2016 Death Note Watty Awards.

(cover art by SYangLau of DeviantArt)
(Rated R due to death, minor graphic content, infrequent swearing, violent themes, abuse, and references to rape and suicide)

"And the notebook Aizawa brought down from the Japanese Investigation Headquarters. Are they real?"
This was the final threat Yagami Light had posed as Kira, pointing out that the notebooks may have been fake. Near knew the one he had was real, since he could see Ryuk, but what about the one Aizawa had brought? Light had plenty of chances to swap it for a fake.
What if this wasn't a bluff, and there was truth in Light's words? What if the final Death Note remained on earth, waiting for someone to take it? What if Ryuk was to come down once more?
And what if there are more Death Notes to come?