Come. Lets go to the simultaneously oldest and newest fun Holy Grail War, humanitys last Master.
It's Golden Week and time to open up the official communication channel for the first time in more then two years between Chaldea and Seraphix, a distant oil drilling platform owned by Chaldea in the Pacific Ocean. Unfortunately, the only message coming through is a cryptic SOS dispatch repeatedly asking for help. Fortunately, across time and space, the spectacular superior Artificial Intelligence BB is here to help! She informs them that Seraphix has somehow been transported to the distant future of 2030 into the Mariana Trench, where it has been sinking for a while. And just for them, BB'll use her hacking skills to allow Chaldea's rayshifting systems to transport the protagonist to the future for this occasion.
Then she interferes with the rayshift, dispersing Chaldea's Servants in random locations in Seraphix and welcomes the protagonist to SE.RA.PH, a digital world of Virtual Spiritrons created by digitizing the sinking oil rig where only the strong survive and Servants must kill one another to earn their way out. With no Servants with them, they seem to have little chance of surviving before a woman with strange bladed legs and the same face as BB saves them, offering an alliance to work together and defeat the other 127 Servants.
Act 1: Swan Lake Returns
Act II: The False-Stepped Coppélia
Act III: The Nutcracker, Once More
Act IV: The Sinking Beauty
Epilogue: Palladion That Tears Through Time
Bottom Black Encore!
- Ascended Extra: The manga adaption makes Ishtar one of the sentinels when she originally was just a random enemy fought in the singularity.
- Bait-and-Switch: Nero, Tamamo-No-Mae and Nameless (EMIYA) were supposed to be the ones that accompany the Master of Chaldea to SERAPHIX, as a call back to Fate/Extra CCC, wherein they're the selectable servants of the protagonist. Here, it's Gawain, Tamamo Cat and Emiya Alter who accompany you on the main adventure, while those three get captured by BB/GO and turned into her own personal Sentinels for the Encore act.
- Even before that, during pre-release press for the event, it's presented as a light-hearted beach resort event called "BB Strikes Back. Let's meet in the digital sea!" Upon release the website changed so that the site appears to be "hacked" by BB, taunting visitors before revealing the real event. Even the game gets in on it, presenting the same fake logo as the event icon until after the intro.
- Breaking the Fourth Wall: BB does this from time to time.
- Crossover: While it is one to Fate/Extra CCC, it also functions as a semi-sequel with Kiara Sesshouin gaining the powers of her CCC counterpart and BB being sent from the Moon Cell in the CCC timeline to counteract this.
- Darker and Edgier: In comparison to the other collabs, which tend to be Lighter and Softer than their source material, Seraphix is not only far more connected to the plot of Grand Order as a whole, but it also poses some uncomfortable questions about the morality of Chaldea under Director Maris-Billy.
- Debut Queue: This event marked a few additions to the summoning gacha.
- Suzuka Gozen was added to the permanent summoning pool.
- Passionlip, Meltryllis, and Kiara Sessyoin were added to the limited summoning pool.
- BB was the free SR servant that was given to participating players.
- BB casually drops the fact that Chaldea can't Rayshift past 20XX. This would have further implications for Cosmos in the Lostbelt, the game's second act.
- Meltryllis at multiple points lets slip bits of information that she really shouldn't know about and always clams up before giving an admittedly solid answer when noted. It's because she's drawing on her experiences from the first timeline where things went pear-shaped fighting Kiara.
- In the church, the protagonist notes something that looks like some sort of shattered porcelain off in a corner, with Meltryllis saying it's nothing. It's actually all that's left of the "current" Meltryllis, who allowed herself to die so that the Meltryllis from the future could take her place without alerting Kiara.
- Despite BB claiming that SE.RA.PH is her body, the sinking woman in Mariana Trench looks more like Kiara. Turns out there's the third map after the main story is completed, and that one looks more like BB.
- Gone Horribly Wrong: Zepar's attempt at using Kiara to regain his body went pear-shaped as she became too much for him to handle.
- Loss of Identity: This started to happen to Kiara when Zepar possessed her...and then it was turned back around on Zepar when Kiara embraced the darker personality of her alternate selves. The Apocalyptic Log detailing their despair gets a little muddled after a certain point of which one is lamenting their situation.
- "Shaggy Dog" Story: In the end, the Protagonist's and allied Servants' attempts at finding and bringing back survivors are for naught, as EMIYA Alter kills the last human who isn't the Protagonist onboard Seraphix (the "other" one having been Kiara all along).
- By the end of the event, the existence of SE.RA.PH is classified as a Singularity paradox and just like any other Singularities, those who directly connected to it "get repaired" into the correct course of time and the memory of the Singularity disappears. Seraphix was dismantled before the Grand Order, the protagonist's recollection about everyone from SE.RA.PH dips in and out of the memory limbo until Ooku, and Melt, who went through a lot to save them, dies and the summonable version of her is the different one who has no idea why her Master makes sad faces when she acts aloof.
- Temporary Online Content: Infamously, despite containing background lore and information that is crucial to understanding the overarching plot of Epic of Remnant and even Cosmos of the Lostbelt, the chapter is treated in-gameplay as an event, meaning that its only available for a limited amount of time. That said the event was later rerun with new side content focusing on Kingprotea, who was added at the same time. With the release of the Main Interlude update, it seems to be averting this.
- Unexpected Character: The manga adaption has the Big Bad of the Fox Tail manga Kazuradrop working for BB.
- What Is This Thing You Call "Love"?: Deconstructed. As a Demon God Pillar, Zepar has a warped and alien view on things that makes it incapable of understanding the concept of love, romance, and passion. As a result, when it possessed Kiara and began experiencing passion and desires, its alien view became unable to rationalize it and became addicted to it, which allowed Kiara to easily reverse his possession and gain control over it.