"You desired all of this! Smile a little! You're contradicting yourself!"
—Nyarlathotep, Persona 2: Innocent Sin
Nyarlathotep (ニャルラトホテプ, Nyaruratohotepu) is a recurring demon in the series. He is given a prominent plot role, known as The Crawling Chaos, as the counterbalance to Philemon in the Persona series.
Nyarlathotep was created by H.P. Lovecraft and is a fictional character in the Cthulhu Mythos featured as an Outer God. He is also symbolic of the destructive potential of Carl Jung's collective unconscious and actively seeks to agitate our universe into madness, woe, and discord.
Nyarlathotep's original character design, first seen in Shin Megami Tensei II, is actually a composite character based on several different monsters from Lovecraft's writings. While its dark, featureless appearance resembles The Black Man, one of Nyarlathotep's "1000 Masks", it is even more evocative of the Nightgaunts: black, featureless, bat-winged nightmare monsters originating in Lovecraft's "Dream-Cycle" stories such as The Dream Quest Of Unknown Kadath. The pincer-like hands and spiny crown reference the Mi-Go: crablike, winged fungoid aliens with a mass of feelers in place of a head first appearing in The Whisperer In Darkness.
Unlike Philemon, Nyarlathotep is able to operate in the outside world and take an active role. Throughout the series he employs the use of Shadow Selves of characters to accomplish his goals. Shadow versions of Tatsuya Suou, Lisa Silverman, Eikichi Mishina, Maya Amano and Yukino Mayuzumi appear as bosses in Innocent Sin. In Eternal Punishment, Maya Amano, Katsuya Suou, Ulala Serizawa, and Baofu all have Shadows Selves which attack the party as bosses in pairs. Nyarlathotep is also capable of appearing as anyone he chooses.
Nyarlathotep (known as Massacre in the original US release) is the persona of Takahisa Kandori. After Kandori is defeated by the protagonist and his friends, Nyarlathotep forcibly enters Kandori's body and transforms him into God Kandori, saying he will grant him the power he seeks. Retroactively, Nyarlathotep has been mentioned to have engineered the whole incident with the intention of giving the humans a chance to destroy all of reality, allowing him to win his bet with Philemon.
A alternate form of Nyarlathotep can be fused in the Velvet Room by adding the "Faceless Mask" item, received after reuniting with Maki Sonomura after Kandori's death, to a fusion with a Tower Arcana Persona result. Nyarlathotep has "Worst" affinity with every party member except for Reiji Kido, Kandori's half-brother.
Both he and Philemon are acting on a bet to see if humanity will become enlightened or ultimately destroy itself. Nyarlathotep decides to push things in his favor by helping humanity end. He appears as Akinari Kashihara, Jun Kurosu's late father, and Hitler, whom was supposedly revived by rumors.
Nyarlathotep fulfills the same role as he did in Innocent Sin. While he does not restore Tatsuya Sudou's memories of the events from the previous game, he does talk to him and tease him with comments intended to spark the general idea of the same events in Sudou's addled mind, so he would be driven to repeat them in the Other Side. He appears before the party as Tatsuya Suou. It is revealed later that the Time Count is Nyarlathotep in disguise.
Nyarlathotep is described as the destructive side of Humanity's collective unconscious, and as such, the living embodiment of Mankind's collective evil; every thought, action or feeling that derives in experiencing the desire to bring harm to others or oneself in any form fuels Nyarlathotep's existence. His reason for providing the human race with the means to drive itself to destruction is given as a bet between him and Philemon, who holds that they instead will ascend to a greater destiny.
Because of his past defeat in Innocent Sin, he took the opening Tatsuya Suou provided him with when he refused to abandon his memories of the Other Side, implementing a new plan to let Mankind destroy itself, and branded Tatsuya with a mark to symbolise the doom that would befall Humanity should either Maya Amano, Eikichi Mishina, Lisa Silverman, or Jun Kurosu regain their memories of the events of Innocent Sin, and delighted in tormenting him as Tatsuya Sudou attempted to force the restoration of the hidden memories with a terror campaign similar to the one he had followed on the Other Side.
In the end, a new group, formed by Tatsuya, Maya, Baofu, Tatsuya's brother Katsuya, and Ulala Serizawa again stood against him and his plans of extermination. However, following his second defeat, he was banished to parts unknown. He wasn't destroyed forever, though, because he is an undeniable, indelible presence in Humanity's heart, and may still return.
"A god of the Cthulhu mythos. He came to Earth in ancient times from outer space and is known as the Crawling Chaos. He acts as a proxy to his masters such as Azathoth, who have no intelligence to make their desires manifest in our world. Because he can assume various forms, he is known as a faceless god. He is particularly known as the Haunter of the Dark, and he seems to have other guises on Earth as well."
"A god of the Cthulhu mythos. He came to Earth in ancient times from outer space and is known as the Crawling Chaos. He acts as a proxy to his masters such as Azathoth, who have no intelligence to make their desires manifest in our world. Because he can assume various forms, he is known as a faceless god. He is particularly known as the Haunter of the Dark, and he seems to have other guises on Earth as well."
—Devil Survivor 2 Compendium
Nyarlathotep appears as the strongest member of the Vile race.