destroyer of time.
what the future brings; the boy and his prophecy
Upon learning the truth that he was a vessel for the 14th's awakening, Allen was determined that he would always be an exorcist, and he would die before becoming anything else. He even requested to his friends to kill him if he ever lost to the 14th. So far, Allen has survived from Nea's attempts to take over his body for multiple times, but can he do this forever?
In the past, when Allen was still in shock after his first encounter with akuma (Mana), Cross and Mother were talking about how the 14th will completely take over Allen's body when the time comes. I think there are already too many hints that the 14th would finally overcome Allen's consciousness, and no matter how much I love Allen, I think that would be a necessary plot device.
If so, then what would become of Allen/Nea?
When Allen first joined the Order, he was examined by Hevlaska, who was also capable of fortune-telling. This was what she told Allen:
"Allen Walker... Sometime in the black future, your Innocence will create a Destroyer of Time." — Hevlaska to Allen Walker, chapter 7.
According to Komui, Hevlaska's prophecies were usually correct. Bookman also believed it, and he analyzed that the word "Time" refers to "Millenium". He believed that Allen Walker could be the one who will defeat the Earl. However, if you compare it to Nea, it might lead to a totally different output.
"I am the 14th Noah who will destroy everything... Nea." — Nea to Allen Walker, Chapter 198.
As mentioned in the previous section, Nea's purpose was to kill the Earl. This part wouldn't contradict Bookman's thoughts on Allen. Killing the Millenium Earl might be a good thing, however becoming a new one doesn't sound like a good idea. I wonder what he aims to do by becoming the next Earl. Destroying humanity? That's likely, but then I wonder why killing the Earl would be necessary. If it really was his true purpose, though, then there are 2 possibilities that I can see. One, maybe the "time" in "Destroyer of time" can be taken literally: he destroys the time—the world. Two, if Nea becomes the next Earl, Allen's Innocence might somehow save the day and destroyes Nea himself.
Considering how General Cross has always been involved with the whole Nea revival project, I think they might have a good plan. Or at least Cross might know how to handle it if things get messy? I mean, Cross might cheat and all, but he's not an —evil— person. I want to have a little faith in him and Nea... and of course, Hoshino.
hidden relations.
98% of the facts about Nea, his story and relationship with other people are still lurking around in the dark. So far, we've only got to see his face once, and the fact that he's the little brother of Mana Walker.
When Allen saw Nea's face, he mistook him for Tyki Mikk because they look so much alike. Now this fact led to a big question: Is Tyki somehow related to Nea and Mana? In this image on the left, Nea and Mana looked like twins from behind, and Mana's hair looked so much alike the current Tyki.
The only people aside from the Earl who knew about Nea's past—which has yet to be revealed—were Road Camelot and Wisely. Wisely also noticed that Tyki's current appearence looked like a certain someone, but Road asked Wisely to keep it a secret.
In chapter 205, we also learn from Road that Mana's "Don't stop. Keep walking" motto was originally Nea's words to Mana. Road also said that Nea fought for Mana. She wanted Allen to keep it a secret, as well. She surely knows a lot about Nea (and maybe Mana). I'm starting to wonder if Road cared so much about Allen not only because of his interesting personality, but also because his body hosts Nea's soul. Those two might have had a close (might be secretive, too) relationship in the past. That would explain her clingyness towards Allen and Tyki. Of course my theory could be wrong, too, because in her relationship chart shown in CharaGray, Road simply said that the 14th was a traitor.