The Yasakas are related to Old Man Henderson
Nyarko muses in Episode 3 if Miharo is related "to the cursed deity hunter in the black book!?" His mother is able to take on Mythos deities using just forks. They're able to communicate and live with Nyarlathotep, Cthugha, Cthulhu, AND Hastur, and still not go insane.There's only one person that could do this: a man cursed with insanity who actually destroyed Hastur. The only answer is that Miharo and Yoriko are descended from Old Man Henderson - The Man Who Won Call of Cthulhu.
Aisora is Yoriko's mentor
It explains why the Author Avatar accompanies her on her adventures. A certain deity will show up as a shady, full-figured woman in a trenchcoat who sells extremely disturbing porn.
Y'golonac (you fool, you've awakened him!) is the god of depravity and assumes the form of an obese, headless man outside his prison, so it wouldn't be too outlandish to think his cutesy counterpart would be fleshy and deal in shockingly filthy videos/games/books. Nyarko isn't the Nyarlathotep, or nearly as horrible
Let's face it, there's no way Mahiro x Nyarko isn't going to happen. His biggest hang-up (aside from her Manic Pixie Dream Girl nature) is the idea that the perky teen girl is just a mask for a terrible, formless cosmic horror. However, in episode 1 of the second TV show, she outright says "They call me Nyarlathotep, but I have a real name". And we already know that she likes to lie in order to mess with people (IE, claiming she's pregnant). So perhaps she's actually just a regular Humanoid Alien who claims to be a tentacle beast just to play with Mahiro's head, and there'll be a reveal in time for them to become an Official Couple. Mahiro will become a Henshin Hero like Nyarko.
It has already been established that Mahiro inherited some of his mother's combat skill, and his knowledge of Lovecraftian lore makes him oddly capable of dealing with the weirdness of his day-to-day life. On top of that, the "good luck charm" Nyarko gave him is, in fact, the The Shining Trapezohedron
, one of the most powerful artifacts in the Cthulhu Mythos, which is linked to Nyarlathotep and can summon a creature called the The Haunter of the Dark. Combining this tidbit with Aizora's love of Toku, we'll probably see the Trapezohedron be installed into a Kamen Rider-style belt that allows Mahiro to draw upon some of Nyarko's power and become the Hunter of the Dark. Nyarlathotepan, Cthughan, and Hasturan don't reproduce the way we Humans do.
They reproduce by staring at each other for a set amount of time. Their eyes would work as a sort of genetic scanner, they then use this to scan their mates DNA and make an exact copy of it, they then add it to the egg in them(or whatever the things called) and badda-boom, that provides the second half of the DNA for the offspring.That would explain how Hatsur could have Mahiro's child, males and females can bare the offspring. Mahiro was right all along.
Nyarko is actually just a cosmic abomination who is messing with him for the lulz, and every other character not from earth is just joining in on the fun. The girl's genders are only aesthetics
While you could shrug it off as Japanese perviness as their literary counterparts are somewhat male (or at the very least use male pronouns), I argue that they're technically still male (if they were male to begin with anyway) and their human forms only appear to be teenage girls because they love anime that much and teenage girls are... shall we say, rather common. Or alternatively, the girls are actually transgender aliens
In relation to the above. When Lovecraft and Derleth wrote about them, they are still male and then they realized they want to be girls, changed their gender and transitioned so at the events of the anime they are already girls making them transgender aliens. This explains the discrepancy why (Cthugha and Nyarlathothep for instance) they are male in Lovecraft's works and then suddenly girls in the anime. So, Cthuko is actually a straight guy... Nyarlathotep him/her/itself gave Manta Aisora the idea of Nyarko as the means of creating a new Cult.
Nyarlathotep saw all of the love and adoration Haruhi was getting and decided to copy her success as a means to ensnare new followers in the Modern Age. If Nyarko appears in your dreams offering to be your girlfriend in exchange for a favor: DO. NOT, LISTEN, TO. HER.
"All Hail Nyarlathotep, The Silver-Locked Schoolgirl! All Hail Nyarko-san! Eat it, Suzumiya!"
— High Priest of the Church of The Silver-Locked Schoolgirl, 2013
