On the eve of the Great Holy Grail War, Ruler summons a Servant to aid her in duties as mediator. Answering her call, Saber appears. A knight whose ties to the Holy Grail War runs deep. Both set out on their journey, soon realizing that an even greater conflict was on the horizon. Uniting both Red and Black, a battle to save the world begins. This is the tale of a Saint and a King.
— Fate Magnus Bellum, the summary of the story
Fate/Magnus Bellum
is a Fan Fic in the Fate branch of the Nasuverse, being something of a crossover story between Fate/Prototype and Fate/Apocrypha with elements from other Fate entries such as Fate/Zero, Fate/kaleid liner PRISMA☆ILLYA, and Fate/strange Fake thrown into the mix as well. It is written by 00Altair, an up and coming author on the site.
The plot of the story starts in a similar fashion to Fate/Apocrypha- Jeanne d'Arc is summoned as Ruler, overseer of the Great Holy Grail War, but she quickly summons Arthur Pendragon as her Saber-class Servant to protect and aid her. It is quickly revealed that the Servant roster of the Red and Black Factions are different and there are more than 14 Servants at play, with a third Faction operating behind the scenes serving as the Big Bad followed by a fourth Faction.
As of February 14, 2021, the author cancelled the story, but said it would eventually be rebooted.
There's also another story in development, which was previewed in the fanfic's Anniversary Extra Act Chapter, that will be entitled Fate/Lunar Regalia, a spin-off that takes place around a year or so after Magnus Bellum, featuring Shirou, Hakuno (the female protagonist), and Servant Saber (Musashi Miyamoto) as the main cast with story elements and setting based off of Fate/EXTRA so far.
Fate/Magnus Bellum contains examples of:
- Accidental Pervert: During Chapter 16, Arthur walks in on Jeanne while she's bathing. Unlike other instances of this trope, both sides are able to maintain their calm (though Jeanne is thoroughly embarrassed nonetheless) and even hold a conversation with each other through a curtain.
- Adaptational Badass: Hundred-Face Hassan, where here he's able to make proper use of his multiple personas to be an actual threat in battle.
- Adaptation Amalgamation: As a fanfic that takes on elements from multiple different Fate entries this was bound to happen. The most notable changes of which are:
- The origin of the Holy Grail War. Much like in Fate/stay night, the Holy Grail War was conceived by the Tohsaka, the Makiri, and the Einzbern families during the 18th-19th Century. However, unlike in canon, it's revealed that Einzbern's didn't truly create the Holy Grail themselves as it was based on the blueprints of the original grail that were stolen by a corrupt cardinal much like in the Fate/Prototype timeline. Also, much like in the latter timeline, the Holy Grail War takes place in Tokyo instead of Fuyuki.
- The events of the Fate/Apocrypha version of the Third Holy Grail War and the Holy Grail War of Fragments of Sky Silver are combined into one. Resulting in both Arthur and Amakusa knowing each other as individual Servants who fought in the same conflict, and as well as having both Manaka and Ayaka be several decades older than they are in canon.
- Adaptational Heroism:
- Gilgamesh is MUCH less of a dick than he is in Fate/stay night, exemplified by how he treats Berserker-Lancelot as a Worthy Opponent in contrast to Fate/Zero, where he viewed him as an affront to his pride. This is partly due to the author basing Gilgamesh's personality here on his Fate/Prototype incarnation, where he was more of a Noble Demon character.
- Medea is much friendlier compared to how she was in Fate/stay night thanks to her overall situation as a Servant being better.
- Adapted Out:
- The servant roster is rather different than either Fate/Prototype or Fate/Apocrypha, so certain servants from each work are absent.
- Among the servants of the Third Grail War, Berserker and Caster are different. In canon, Berserker was Jekyll & Hyde, while Caster was Paracelsus. Here, Berserker is Heracles and Caster is Tamamo no Mae.
- Rather than summoning Frankenstein's Monster, Caules summons Elizabeth Bathory as Berserker of Red.
- Instead of summoning Avicebron, Roche summons Medea as Caster of Black.
- Jack the Ripper isn't summoned by the Black Faction as the Assassin of Black, rather Hassan of the Hundred Personas is. Neither of her masters, Hyouma or Reika, are present either, rather Hundred Personas' Master is Julian Ainsworth.
- Instead of Spartacus being summoned as the Berserker of the Red Faction, Lu Bu Fengxian is summoned instead.
- Averted in regards to the Archers, Riders, and Lancers of Red. Atalante, Karna, and Achilles are all still summoned, just not as they were in canon. Achilles is summoned as the Lancer of Red, whilst Iskander is summoned as the Rider of Red. Atalante and Karna are still summoned in their respective classes but as Servants of Shirou Kotomine's Rogue Faction. Instead, Gilgamesh is summoned as the Archer of Red.
- The servant roster is rather different than either Fate/Prototype or Fate/Apocrypha, so certain servants from each work are absent.
- The Alliance: The Red and Black Factions as per the original canon. As of ACT-2, said factions unite in order to take on the Rogue Faction and Manaka. They even refer to themselves as this trope.
- Ascended Extra: Reines El-Melloi Archisorte. She was originally just a minor character in Fate/Apocrypha, but here she's the Master of Archer of Red. Similarly, Waver/Lord El-Melloi goes from a cameo to the Master of Rider of Red. Siegfried as well as he has more prominence in the story than he did in canon.
- Badass Boast: Iskander has a good, long speech of this when he activates Ionian Hetairoi. Karna also has a good few ones, but unusually, he isn't being arrogant or condescending about it: he is completely sincere about his awesomeness.
- Badass Transplant: Sieg gets a dragon heart implanted in him courtesy of Medea, which gives him the ability to shift parts of his body into a dragon and breath fire.
Word of God notes that it takes many cues from Corrin of Fire Emblem Fates, and adds that default male-Corrin and Sieg are very similar in appearance. - Berserk Button: Several of them in fact.
- Though Mordred is already volatile by nature, one does not treat her like a woman or bring up her relationship with her father in front of her without pissing her off almost immediately. Otherwise, they'll be on the receiving end of Clarent.
- Vlad III doesn't take well when they talk of Dracula.
- Gilgamesh is furious when he hears that the Third War's Rider boasted to be the "King of Kings".
- In a similar vein to Gil, Perseus becomes a living one to Achilles, after Perseus ganged up on Chiron with some of Assassin's manifestations instead of fighting their old master one-on-one.
- Big Bad Ensemble: Shirou Kotomine and Manaka form one at the beginning of ACT-II. Both having their own goals separate from one another.
- Brainwashed and Crazy: All of Manaka's Servants are this in one way or another as they wouldn't follow her orders otherwise.
- Broken Ace: Arthur, who is plagued with self-esteem issues thanks to his past. This is even more apparent in his interactions with Mordred and Guinevere, where it turns out he rejected Mordred when he was in the midst of a Heroic BSoD from his son, Lucius, apparently dying from sickness.
- Butt-Monkey:
- Robin Hood, who regularly gets abused or poked fun of in most of his appearances.
- Hundred-Face Hassan. Who, much like in Fate/Zero thanks to their numbers as well as the nature of the Class-Cards in the story, is treated as fodder despite him being also a case of Adaptational Badass in it. It gets to the point that Robin casually uses one of the personas as a shield to prevent himself from being killed by Cu Chulainn.
- Elizabeth and Caules tend to get the short end of the stick in some situations too.
- The Cameo:
- A certain Red Dragon Emperor's pair of idiot friends make a short appearance in Chapter 19 commenting on Elizabeth, Astolfo, and Mordred. The latter does not take it well.
- The appearances of Shirou, Issei, Hakuno, and Aoko in the Side Act could count. With Shirou and Hakuno even commenting on news about an explosion occurring in a forest near the Tokyo Area. Which was actually a result of Arthur's battle with Richard.
- Character Development: Quite a bit of it, surprisingly. Mordred is as of the recent chapters beginning to move past her issues regarding Arthur, and Arthur himself gives up his wish after a good, long talk with Guinevere and decides to live for the future.
- Cool Bike: Arthur gains use of a motorcycle early on, later fully given to him by Sister Petresia. The Gil-Gil machine makes an appearance as well, obviously owned by you know who.
- Covert Pervert: In contrast to her usual demeanor, Jeanne is clearly this trope. She gets too into thinking about how Arthur conceived Mordred despite his apparent physical age, as well as being the one most likely to pick up on
accidental sexual sentences. She even blushes immensely and can't think straight when Arthur walks in on her in the bath. - Curb-Stomp Battle: As usual, Gilgamesh doesn't even try when he basically annihilates Robin Hood in Chapter 10. Manaka and Berserker also easily defeat Darnic and Vlad III.
- Death by Adaptation:
- By the second chapter of ACT-2, Chiron is now dead, whereas in the original, he is still alive and kicking until the end phase of the Great Holy Grail War.
- Gordes as well, who in the original managed to survive the war.
- Death Is Cheap: Somewhat the case in regards to the Class-Card Servants, as they can be summoned again so long as their cards remain intact, though they lose their memories every-time they die. It's later revealed that this also applies to Manaka's Servants thanks to her abilities and they are even able to retain their memories.
- The Dreaded:
- Dude Looks Like a Lady: Astolfo as usual. To the point that not even Jeanne can determine his gender with her abilities as a Ruler.
- Exact Words: Arthur exploits this in regards to Shirou using a Command Seal to force him into suicide at the end of the Third Holy Grail War. He told Arthur to kill himself but didn't specify how. To which, Excalibur begins glowing...
- Foreshadowing: In Chapter 5, during Mordred's flashback, it is clearly stated that she is Arthur's eldest child. Sure enough, his youngest child was a major catalyst in Arthur rejecting Mordred- Lucius had apparently died from an illness around the time Mordred revealed herself, and Arthur was too deep in grief to properly react which set off her rebellion and the fall of Camelot.
- Green-Eyed Epiphany: Being in denial of her feelings for a while, it takes Arthur admitting that he still loves Guinevere and Jeanne subconsciously becoming jealous as a result for her to finally admit to herself that she's in love with him.
- Hero-Worshipper: Rogue Saber, aka Richard the Lionheart, is this to Arthur. Though, considering his legend, Fridge Brilliance kicks in when you remember one aspect of his legend.
- Irony: The Holy Grail itself is the only way that Arthur can ascend to become a true Heroic Spirit due to not being completely dead. However, as Jeanne's servant, he is incapable of taking part in the war and winning the Grail due to her status as a Ruler-Class servant. He's aware of this, but he accepts the reality of his situation.
- Killed Off for Real: As of Chapters 14 and 15, six characters have officially kicked the bucket. Lu Bu, Chiron, Darnic, Vlad, Gordes, and Celenike. The latter four of which don't even get a death scene, especially Gordes and Celenike. As of the third act, Iskandar, Robin, and Hassan of the Hundred Faces have joined the list.
- A Lighter Shade of Black: The Rogue Faction is this to Manaka's faction. While Shirou's group is composed of Affably Evil well intentioned extremists who want to use the Holy Grail to rid humanity of evil and have moral lines they won't cross, Manaka's group is composed of Brainwashed and Crazy Servants led by an Ax-Crazy yandere whose endgame is to bring forth the Beast of Revelation and the destruction of the current world.
- Love Hurts: Jeanne once she realizes she's in love with Arthur as she realizes how next to impossible them getting together is thanks to their situation. Not helped at all by the fact that Arthur hasn't gotten over Guinevere either.
- Mêlée à Trois: As of ACT-2, the Alliance, Rogue Faction, and Manaka's Faction are fighting against each other for the Original Grail and the Greater Grail.
- Mythology Gag: A few to the series the fanfic draws on:
- Gilgamesh fights Lancelot on two separate occasions in Fate/Zero. They do the same thing in this fanfic, albeit with some slight differences and for different reasons.
- Iskandar mentions that if Arthur had regretted his rule at the banquet, he'd have to scold him. On the whole, the banquet really is just taken from Fate/Zero, but with more characters and with a different ending.
- It's noted in Fate/Apocrypha that the only one who could fight Karna on an equal footing would be Achilles. Here, they have a brief fight when the Rogue Faction attacks the Black Faction's castle, and they are indeed quite evenly matched.
- Brynhild notes that Siegfried is very similar to Sigurd in appearance and personality, such that her curse goes into overdrive almost immediately.
- Oblivious to Love: Arthur towards Jeanne.
- Odd Friendship: Karna and Atalanta grow to have something of a good relationship with each other.
- Pet the Dog: Gilgamesh gets several moments here, such as letting Achilles getting piss drunk after the latter finds out Chiron got killed by Perseus, as well as giving Fiore a cure for her paralysis that would let her keep being a magus. Naturally, Gil just says he did it for no reason but Reines knows better. It's also implied he partially did both things due to being reminded of his one true friend.
- Related in the Adaptation:
- In this universe both the Tohsaka and Sajyou families are related to each other. Ayaka herself is the grandmother of Rin, Sakura, and Aya, the latter of whom is based on the Ayaka Sajyou from Fate/strange Fake.
- The second bonus act also reveals that Elsa, Arash's Master from Fragments, is a Tohsaka herself through marriage, going by Saijou as part of her day job, and is Ayaka's adoptive mother as well.
- Ship Tease: Between Arthur and Jeanne, Caules and Aya, and Karna and Atalanta. Especially for the former once ACT-2 rolls around.
- Those Two Guys: Astolfo and Elizabeth are usually seen together and get along well. Though the latter doesn't take kindly to the former's rather effeminate looks and how it overshadows her own.
- "The Reason You Suck" Speech: In Chapter 20, Jeanne gives one towards Mordred after getting sick of her attitude. In contrast to most examples, Jeanne does this not to tear Mordred down but to make her aware of her own flaws and make her realize she needs to surpass them if she wants to be as great as Arthur is.
- "Well Done, Son" Guy: Mordred. Which comes in full force this time around with her father now present as Jeanne's Servant.
- Well-Intentioned Extremist: Shirou Kotomine as per canon, since his main goal is to use the Holy Grail to rid mankind of evil. Manaka reveals herself to be somewhat this, wanting to destroy the current world in order to create a new one where Arthur's wish can come true.
- Wham Episode:
- Chapter 13. Manaka begins to make her move.
- By the next chapter, she brings out Heracles and kills both Vlad and Darnic. She reveals the original purpose of the Holy Grail War to the major characters and takes the Trifas Grail for herself.
- World's Strongest Man: Gilgamesh, as usual, with him being the strongest by virtue of a combination of his fighting skills and abilities.
- Worthy Opponent: Too many to count. But a special mention goes to Cu Chulainn, who gets Karna to view him like this after the former bypasses his armor with Gae Bolg, giving him his first real injury in the war.
- A second specific mention as well are Arthur and Rogue Saber Richard the Lionheart. During their first bout, they are easily matched and Richard gives Arthur his first real injury of the Holy Grail War that even Karna wasn't able to give him. In the following chapter, Arthur expresses the sentiment of wanting to fight Richard again.
