This is part 2 of a two part story. Part 1 is called Shin Megami Tensei: Digital Devil Saga
In an open field in the Junkyard, a giant egg-like object with tentacles with no apparent origin appears on the border between the Embryon and the Vanguards, causing a stand-off where both assume the other group placed it. During this confrontation the egg explodes and a virus is introduced that infects everyone in the Junkyard, turning them into demons. Branded with a mark representing their "Atma" and gradually awakening to basic emotions, the people of the Junkyard must devour their foes to satiate their demonic hunger or risk going berserk. Sera, a so-called cyber shaman, is found in the crater where the egg exploded, suffering from amnesia. She is taken in by the Embryon, revealing herself capable of calming their hunger with her singing. The Embryon first become conscious of their new powers when they meet the surviving Vanguards. During their time there, they are forced to kill the Vanguards' leader, Harley. Serph is then summoned to the Karma Temple along with the surviving tribe leaders. Once they are assembled there, a female being calling itself Angel orders the tribes to conquer their neighbors and ascend the Temple's tower to "Nirvana", bringing Sera as proof of their achievements. The Embryon decide to ally with the Maribel as a means of defeating the stronger tribes.
These characters are able to transform into a demon form, which is their main form in battle. Characters navigate to-scale environments, fighting enemies in both random encounters and story-focused boss battles. After each battle, experience points are awarded to characters. Character abilities are governed by Mantra Grids, a system where Mantras are bought using the in-game currency Macca, then mastering them using Atma Points gained from defeated enemies. The maximum number of abilities that a character can learn is eight. If two or more characters equip a certain ability, they can perform a stronger version of it through a combo. Each character can learn abilities from one of four categories: Physical, Magic, Shield and Auto. The Digital Devil Saga games use a turn-based battle system, with three allied characters fighting in battle. Both player characters and enemies are governed by a mechanic called the Press Turn system: each character has a symbol representing a turn. The character can forfeit a turn to allow the next character an action; turns cannot be passed more than once. If an enemy's weakness is exploited or a character lands a critical hit, an extra turn is gained; if a character resists an attack, a turn is lost. In Digital Devil Saga 2, characters will sometimes enter battle in a half-transformed "berserk" mode, which increases attack power while locking away magic skills and lowering a character's defense. While battle is focused around strengthening characters' demon forms, they can also fight in their human forms using conventional weapons, and can equip ammunition. A human character can perform a combo with one in demon form. The magic system uses nine magic attributes. Ice and Lightning magic have a chance of causing the "freeze" and "stun" status, while Expel magic reduces an enemy's hit points by a certain percentage, and Death magic causes an instant kill. Status magic can inflict status effects on enemies.
Source: Wikipedia, "Shin_Megami_Tensei:_Digital_Devil_Saga_2," available under the CC-BY-SA License.