Long into the future, Earth has become a radioactive mess thanks to a war from a thousand years ago. Humanity is also extinct except for Draconic Humanoid beings that clean up the pollution. The only island with ordinary humans is the island of Arzenal, where those who resisted the toxic substance called Norma live.
Then all of a sudden, an interdimensional portal opens up and releases waves of military-grade weapons that cause havoc on their planet. Recognized by their markings and Tron Lines, these were forces of Mana, former oppressors of the Norma who have now returned. The leader? None other than Sylvia Ikaruga Misurugi.
Cross Ange: Futatsu Sekai No Border (translates to Border of Two Worlds) is a continuation of Cross Ange that focuses on the Mana people after the Apocalypse, which took away their Mana and caused widespread destruction from releasing Aura. The once dominant race on the artificial world is now left to fend for itself, suffering constant food shortages, ruthless attacks from the Norma left behind, and serious amnesia over their own crimes. Supreme Commander Alexia and her Reunion army lead the society of True Earth in persecuting the Mana people as revenge for the years of suffering the Norma endured. Among the survivors is Sylvia, who leads her new army as they rebuild and reform the Mana society and launch a new war against the True Earth.
The fic can be found here.
Cross Ange: Futatsu Sekai No Border provides examples of:
- 20 Minutes into the Future: The beginning of the fanfic.
- Absurdly Sharp Blade: Eric "The Reaper" manages to cut Para-mails with a small katana.
- After the End: After the "Apocalypse", when Mana lost its Light.
- Amnesiac Dissonance: The majority of the Mana populace remain oblivious over the crimes they committed during Embryo's time. Only a few were able to retain all their memories such as Sylvia, and those who do remember are traumatized over what they've done to their friends and family.
- Asshole Victim: Subverted with Ahiko. On one hand, she sold out the canon main character of the story and chanted for her execution. On the other hand, like the rest of Mana, she suffered Laser-Guided Amnesia and got sodomized, raped and tortured to the point her hatred for Norma became solidly reasonable. If that wasn't enough, she would've been lynched by families who once had Norma children.
- Big Bad: Supreme Commander Alexia is the leader of the Reunion army, an organization of Norma who work for the True Earth and seek revenge on the now-powerless Mana people for their oppression; as such, she leads the Norma in attacking and persecuting the Mana people.
- Cool Car: The Bulldog, the primary vehicle for Sylvia's group.
- Continuation: It continues the events of Cross Ange after Mana was destroyed, leaving the Mana people powerless, by having the Norma oppress the Mana people.
- Contrasting Sequel Antagonist / Contrasting Sequel Protagonist:
- Sylvia is both this to Embryo, as a Villain Protagonist, and Ange respectively. On the side of Embryo, she is someone Ange knows very well and uses a Flawed Prototype in contrast to the Hysterica. She is also a No-Nonsense Nemesis who defeats Ange effortlessly and a far more sympathetic antagonist who has more than good reason to confront her. On the other hand, she contrasts Ange by taking up the name of Empress despite her objections. She is also coolheaded and is overall a Positive Friend Influence to her subordinates, becoming A True Hero wanting to save everything instead of merely lashing out of spite.
- Create Your Own Villain: The discrimination against Norma instituted by the now deceased Embryo has resulted in the stragglers coming for the ex-Mana users.
- The Dog Bites Back: A very dark version with the Norma left behind who now attack the Mana people in retribution for their abuse.
- Don't Call Me "Sir": Discussed Trope. Sylvia dislikes being called an empress or even a princess, much like her sister. However, many of the survivors consider otherwise since she convinced them that Mana can walk back up its feet.
- Doomed Hometown: Sylvia's first attempts at rebuilding the Mana society ends up getting destroyed by Norma forces. Hilda's sister had her village destroyed the same way.
- The Empire: True Earth, the society of Norma which replaced the Misurugi Empire and is responsible for the oppression of Mana people.
- Expy: The "Bulldog" bear a clear resemblance to the "Dead Reckoning".
- Fix Fic: The fic is a Continuation of the original series that focuses on the Mana people, after the events that lead Mana to ruin. Mana has traded places as being the unfair victims of Mind Control and Laser-Guided Amnesia. The story follows Ange's sister Sylvia, who, after undergoing Character Development to become a heroic Action Girl, helps to show the Mana people in a more complex and likable light than their canonical Always Chaotic Evil portrayal.
- Full-Circle Revolution: Although Mana users can no longer distinct themselves from Norma, the Norma still haven't forgotten the excessive cruelty they received, nor have they recovered their sanity. With exceptions like Sylvia's group and the Kingdom of Rosenblum, every place else is not without sadistic Norma who savagely slaughter entire settlements. A cruel irony where oppressors and erstwhile victims have traded places.
- Gone Horribly Right: Teaching Sylvia to fight has backfired on her older sister big time, if the prologue events are any indication.
- Hero Secret Service: The Misurugi Royal Family (though not exactly heroic) had one of these who devote their lives protecting Sylvia.
- Hope Bringer: Sylvia is viewed as one in the eyes of former Mana users and Norma who were left behind, as she loves, accepts, and fights for them, unlike the new society.
- Human Resources: The Norma drain Mana users of their blood and organs for unknown reasons.
- Laser-Guided Amnesia: The majority of Mana has suffered this. They're left to pick up the pieces of a world they hardly remember and survive the unspeakable atrocities committed against them.
- Like Father, Like Son: Sylvia become the leader of a group fighting the current status quo, just like her older sister Ange. And Hilda's sister becomes a close companion, just like Hilda herself was to Ange.
- The Magic Goes Away: The reason that the Norma were able to become so powerful and tyrannical is that Mana has disappeared, as in the original series, and now the Mana people have no way to fight back.
- Nice Job Breaking It, Hero: The Libertus did anything but liberate the Norma or stop the Mana people's violence against them. All they did was put the Norma on top of the oppression.
- Persecution Flip: In an expected and cruel sense, Mana users are now being savagely abused by the Norma still left behind in the same dimension.
- Recruiting the Criminal: Sylvia acquires more forces by recruiting the former rejects of their society. Justified as she needs every hand she can get now that she has lost her mana.
- Self-Fulfilling Prophecy: The Norma left behind in the post-apocalypse False Earth are now the violent savages they were portrayed as by the Mana due to the abuse they suffered.
- Shout-Out: One squad sent to confront Sylvia is named Francesca, Lynn, and Pirenne.
- Unexplained Recovery: Misty somehow manages to escape her transport aircraft and is playing a role of keeping the Kingdom of Rosenblum together.
- We Have Become Complacent: How the Mana people feel over their past time and their dependence on Mana. The story follows them rebuilding from the ashes.
- Who's Laughing Now?: In addition to the Norma’s violent revenge against the Mana people for their Fantastic Racism, the Mana people themselves not only regain their Mana abilities, but they also wage a one-sided war against the inhabitants of True Earth for their Persecution Flip.
- Woobie, Destroyer of Worlds: The Norma left behind on the False Earth who after losing their sanity from their abuse destroy settlements of once-Mana users.
- World of Action Girls: Played much straighter than the original series, which was a harsh take on the genre.