The second game of the ''Majin Tensei'' series of {{Strategy RPG}}s.

In 1996, a demonic infestation arises in Tokyo lead by someone who overthrows the government in a coup d' etat, turning the city into a demon paradise as a result. An organization known as Partisan is created to fight back against this individual and unravel his Modus Operandi, but before long the situation goes out of control.

Main Characters:
* Naoki Takeuchi (Protagonist): Unusually for a MegaTen protagonist, he actually talks and has his own personality. Uses Swords, Knives, and Firearms.
* Kaoru Tachibana: TheBigGuy of the group, but also has impressive magical ability. Specializes in Katana and Axe use, learns Agi, Zio, Giga, and Megido spells.
* Tomoharu Kikuchi: TheSmartGuy. He gains the ability to summon demons later on. Can use Swords, Knives, and Bows.
* Aya Kikuchi: ActionGirl, can use some offensive magic but specializes in healing. Uses Knives, Firearms, and Staves, learns Dia, Maragi, and Rimudora spells.
* Karen Rose: A mysterious woman who appears in Naoki's dreams, and who apparently knows the cause of the disaster. Uses knives, spears and firearms, but only joins the party [[spoiler: on non-Neutral routes]].
* Ogiwara: The man spearheading the demonic invasion. He is said to be the child of Lucifer himself, which is why he can talk to demons. Can use swords, katanas, and firearms, but only joins on a Neutral route.If you are either Law or Chaos after his conference, he will fight you in chapter 3-10 (aka 29), "Base of Ogiwara" and then die.

!This game contains the following tropes:
* ArcWords: Nemesis, it's even mentioned in the title as Spiral Nemesis.
* AttractiveBentGender: Beelzebub.
* BigBadEnsemble: There are a number of antagonists behind the events of the story. From Beelzebub working with Camael on perfecting DIO and the TimeTravel, to Satan and Michael imposing order upon the earth. Lucifer is the only exception amongst the four despite being the FinalBoss of one route. His role in the story is revealed to be to explain Ogiwaras origins on the Neutral-Neutral Route.
* BrainwashedAndCrazy: Tomoharu as a result of exposure to the DIO system.
* CharacterAlignment: Perhaps the first Megaten game that allows humans to be Light or Dark Aligned along with Law or Chaos, this affects which demons you can summon.
* FinalDeath: Any demons who die will stay dead and can't be revived.
* FunWithAcronyms: DIO, FRI-DAY, and so on.
* GiantSpaceFleaFromNowhere: Ahriman on the Neutral Route, also doubles as the TrueFinalBoss story wise.
* IsometricProjection: This is the only isometric game in the ''Majin Tensei'' subseries.
* KillSat: HELIOS
* MultipleEndings: 5 of them, all based on your alignment.
** LaserGuidedAmnesia The Light-Law Ending. The heroes lose all their memories pertaining to the journey they all took, so that a paradox will not occur. However after her mission Karen is sent back to 1995 where Naoki meets Karen again by chance.
** IChooseToStay: The Light-Chaos Ending. Naoki decides that someone is needed to keep the peace in 2056, while the others go back in time. Tomoharu becomes involved in academics and politics in 1996, possibly leading him to become a public figure, Kaoru searches for his mother in 1995, and Aya helps Naoki's parents in 2024
** SetRightWhatOnceWentWrong: The Neutral Ending. Ogiwara chooses to destroy Megalopolis to prevent Nemesis from existing.
** ResetButtonEnding: The Dark-Law ending, HELIOS is fired at the heroes. It then turns out it may have been AllJustADream / DreamingOfThingsToCome and it was Tomoharu's dream also, not Naoki's, and he wakes up moments before the first meeting between himself and Naoki.
** MyFutureSelfAndMe: The Dark-Chaos Ending. Naoki remains in the future while everyone else is sent back, minus the details of the Light-Chaos Ending.
* MythologyGag: References from the first game are in this. Even some of the music; Devil Dance is used for the Free missions (Purple marks) on the map, Frame Up Fragment is used on the Paranoia maps, and the Satellite map uses Bicarbonate of Face/Fate (Overworld theme of ''Majin Tensei''). In addition the Core of Megapolis is a [[VideoGame/ShinMegamiTenseiII metal pyramid with the top removed]], and HELIOS is fired by [[VideoGame/ShinMegamiTenseiII Satan]].
* NamesTheSame: Naoki Takeuchi from this game, Naoki Konishi from ''VideoGame/{{Persona 4}}'', and Naoki Kashima, the [[VideoGame/ShinMegamiTenseiIIINocturne Demi-Fiend's/Hito-Shura's]] name from the radio play. Also, Kaoru Tachibana from this game, and [[{{Persona2}} Kaoru Saga]].
* NoExportForYou: Much like the first and 3rd ''Majin Tensei'' games, this wasn't ported to the US.
* RareCandy: Much like the other Megaten games, Incenses are in this one. However they cannot be used outside of battle maps.
* TemporalParadox: Karen's goal is to go into the past to prevent anything from interfering with Megapolis' origin.
* TooAwesomeToUse: The Moon Skins recruit demons immediately when used, no negotiation needed. You can even get demons opposite your alignment this way.
* TouchedByVorlons: Kaoru and Aya learn the ability to use magic from Amnesia, the heavenly realm of the angels.
* TimeTravel: To several periods in the future, even one year in time before the first scenario.
* WeCannotGoOnWithoutYou: If any of your humans die, game over.
* WellIntentionedExtremist: Ogiwara. He went back to the past to destroy the DIO system. DIO ultimately lead the Supreme Council to become corrupt and defunct. If the Council is not stopped, the military will perform a complete glassing of Megalopolis.
* WingedHumanoid: Some demons, angels, and Satan and Lucifer, are fought as their humanoid forms rather than their transformed states in earlier and later games in the Megaten franchise.
* {{Zoroastrianism}}: Perhaps the first game in the franchise that features Ahura Mazda in his original form, Verethragna, Anahita, Mithra, and Ahriman.