YMMV / Digital Devil Story

• Accidental Aesop: Don't attempt to use something you don't fully understand for your own gain, lest it blow up in your face and make things much worse for you and those you care about.
• Adaptation Displacement: These books are virtually unknown outside of Japan, and pretty niche even within. Compare that to Shin Megami Tensei, the franchise (initially) based off said books.
• Alas, Poor Scrappy: Kyoko and Kondo may be privileged bullies that beat up both the gifted and common students alike, but they hardly deserve the brutal deaths they receive. Being bitten and torn apart during an otherwise normal day in class, by brainwashed students, scared and begging for their lives while the protagonist can't spare an ounce of pity or regret is a bit much.
• Complete Monster:
  • Reincarnation of the Goddess (first book): Loki is the catalyst for the trilogy as a whole. A demon summoned by Akemi Nakajima to get revenge on two students, Loki orders Nakajima to procure female sacrifices as compensation, including Nakajima's teacher Ohara, whom he impregnates. Initially following the terms of the deal, Loki has a teacher murdered against Nakajima's wishes. Lusting after Yumiko Shirasagi, Loki demands her as a sacrifice and betrays Nakajima when he refuses. He then manipulates the brainwashed Ohara into summoning him into the real world, and goes on a killing spree by devouring countless students and other innocent civilians. He attempts to rape Yumiko, and was only thwarted by the goddess Izanami's intervention, but nonetheless manages to fatally wound Yumiko in the process. In pursuit of the protagonists, Loki murders the loyal Cerberus and Yomotsu-Shikome, and tries to rape Izanami as well. A demon solely driven by his wanton lust for rape and blood, Loki sets the standard for future Shin Megami Tensei villains.
  • Warrior of the Demon City (second book): Set and Isma Feed are the main antagonists. Having heard of Nakajima summoning Loki, Isma heads for Japan after forcing an FBI agent to shoot himself. Meeting Ohara, Isma learns of her contact with Set and proceeds to make a contract with the god. With Ohara useless and demonizing as a result of her unborn child with Loki, Isma sends her on a suicide mission to take out Nakajima and Yumiko, resulting in the slaughter of the latter's family and Yumiko having to incinerate Nakajima's possessed mother in front of him. After Ohara's death, Set takes over her child's body and takes Yumiko, who he and Isma use as a cornerstone for Set's new body—one made out of countless people compelled to sacrifice themselves to become part of Set. When Isma is killed in a battle with the heroes, Set rapidly speeds up the process until the final battle, where he tortures Nakajima with images of his and Loki's victims from the first book, before finally attempting to drop a spaceship on the Earth.
• Diagnosed by the Audience: Something is clearly very wrong with Nakajima, with his lack of regard for other human's lives barring Yumiko and generally superior image of himself. His silent (and often violent) fits of anger definitely aren't what would be considered normal in a teenager, either, with several fans unofficially diagnosing him with antisocial personality disorder as a result.
• Esoteric Happy Ending: Japan and the United States might have been reduced to irradiated, demon-infested hellscapes and most of the cast have met an Uncertain Doom, but hey, at least Nakajima and Yumiko are alive and together again! And don't forget that none of this would've happened had Nakajima not responded to his bullying problem by attempting to summon an evil god to kill his bullies.
• Harsher in Hindsight:
  • A troubled teenager being tormented by bullies concocts a plot to use a powerful machine in order to get revenge on his aggressors, only for things to quickly spiral out of control due to him underestimating the volatile power now in his hands. Sound familiar?
  • Nakajima's story ends up being highly similar to Sahori from Shin Megami Tensei V, who makes a pact with Lahmu to kill her bullies. In the end, Sahori ends up dying, but not before Lahmu, using her body, mortally wounds the protagonist and Sahori's best friend Tao, forcing Tao to give up her human life to save the protagonist.
• Moral Event Horizon: See here.
• Nightmare Fuel: The lovingly detailed descriptions of what Loki does to people. And how he eats.
• Unintentionally Unsympathetic: Nakajima is obviously intended to come off as a Jerkass Woobie who went in over his head and deeply regrets his actions, but the fact that he went into his deal with Loki intending to use him to murder his bullies, was fully on-board with luring in innocent women (including one of his own teachers) for Loki to viciously rape until he targeted someone he personally cared about (which anyone with even the least bit of Genre Savvy would have expected) and wound up ushering in the demonic apocalypse just because he didn't want to lose Yumiko again makes him hard to root for.

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