Especially after watching -man Hallow, I'm sure you all have noticed the similarities between Tyki and Neah. I'm going to elaborate on that here.
A possibility is that Tyki is either a third brother or he's related to them some other way. He may be Neah's long lost son or something. Wisely even pointed out that Tyki and Neah look really similar and Road knows this too. She even told Wisely to be quiet about it. That woman knows to much and the author makes it so she can't tell us. 'sigh'
The fact that almost all the Noah have the last name, Camelot, and Tyki's is Mykk is odd. It's as if his is different for a reason.
I think that Tyki has either Neah or Mana's body. Neah's would more sense in looks, but Tyki and Mana are the same height, 6 foot 2. Plus, Mana has always been shown with long hair. Why would the author chance Tyki's hairstyle if there wasn't a meaning for it? The only other Noah she did that with is Jasdevi. Maybe she did it to try and show how similar Tyki and Mana look.
Since there's the parallel with Neah and Tyki, I think Tyki will betray the Noah. He's taken a liking to Allen and I bet he might come to Allen or Neah (depending on which one's in control) for answers. Mana was brought up in the new chapter and Tyki recognized the name. I forget if he heard Allen say it in the past, but if he did, he may remember Allen telling him, and he'll ask him about Mana.
We all know that Tyki has human attachments, so he hasn't forsaken his humanity. Sure, his Noah has awakened, but we don't know what he's been doing in his free time lately. In fact, he don't even know if he has free time anymore. Long story short, Tyki may have Mana's body or be a child of either him or Neah. Now, all we can hope for is for Road to reveal some stuff about him.
Please tell me any more ideas you have about this theory and I'll do my best to come up with more myself. Bye!