Postnuptial Disagreements is a crossover Fan Fic for Sekirei, Fate/stay night, and Fate/Zero. It is written in first person from the perspective of Meriwether Archibald El-Melloi, the son of Kayneth and Sola-Ui from Fate/Zero, who survived an alternate fourth Heaven's Feel. And he's pretty much exactly what you would expect.
On a trip to Japan to research his parents' role in the Fourth War, Meriwether finds himself stuck in the middle of the Sekirei Plan after Benitsubasa wings herself with him. Naturally, he leaps off the slippery slope with the zeal of a true magus, making the Sekirei Plan a whole lot bloodier in the process.
Benitsubasa soon finds herself trying to deal with the insanity that her Ashikabi has unleashed. And get laid. Which isn't as easy as it sounds.
Postnuptial Disagreements is also noteworthy for a surprising amount of character development over the course of the 'fic.
This fic provides examples of:
- Anti-Hero: Meriwether. Though he might qualify as a Villain Protagonist, depending on your interpretation.
- Anyone Can Die: Many of the 'deaths' are little more than the defensive-comas of Sekirei terminations, but as the finale gets closer, there are a lot of Level Five terminations.
- Big Bad: Karasuba
- Brains and Brawn: Meriwether thinks initially of him and Benitsubasa as this, but it turns out they are far more equal than he thought. The existence of magic is a shock, but Meriweather notes (even before he's fully accepted her as an equal) that she's very good at taking his fantastic abilities and accepting their results without needing to fully understand how they're possible in the first place.
- Character Development: Meriwether AND Benitsubasa, though your mileage may vary.
- Combat Pragmatist: Meriwether learned from the mistakes of his father in the last Grail War.
- Earn Your Happy Ending
- First-Person Smartass
- For Want of a Nail: The specifics are never specified, but Meriweather mentions Kiritsugu Emiya's destruction of the hotel Kayneth was using during the Fourth Grail War, which means that Lancer was killed either in that event or quickly enough afterward that Kayneth never launched the attack that resulted in Kiritsugu destroying his magic circuits.
- Hopeless with Tech: Meriwether
- I'm a Doctor, Not a Placeholder: Kochou, Meriwether's undead hacker."I'm a computer expert, not an oracle."
- Inner Monologue: Magus that he is, Meriwether compensates for his limited external monologues by providing a running commentary on everything from assassination techniques to home furnishing.
- Leaning on the Fourth Wall: This is commented on by Uzume when Merry uses a spell so that they share consciousness.
- The Juggernaut: Miya
- Magically Binding Contract: A favorite strategy of Meriwether is to manipulate or blackmail others into one with him. Later, Higa and Miya use it successfully against him.
- Master Poisoner: Meriwether
- Meddling Parents: Kayneth takes this Up to Eleven.
- Noble Bigot: Meriwether
- Pair the Smart Ones: One of the main reasons why the relationship between Benitsubasa and Meriwhether works is that they both are smart people who seek other smart people as partner.
- Papa Wolf: Dozens of Sekirei and Ashikabis won't stop Kayneth from retrieving his son. Later on, Kiritsugu makes it clear that the qualities separating Meriweather from his parents are the sole reason that he lets Meriweather even associate with Ilya.
- When Kayneth is starting to vivisect Benitsubasa, it's very, very clear that he's not happy about the apparent fact that his son's mind was altered as a part of the Sekirei-Ashikabi link.
- Spared by the Adaptation: Not only do Meriwether's parents survive the Fourth Grail War, but Kiritsugu and Ilya live much longer than in canon. The same can't be said of quite a few members of the Sekirei cast.
- They Would Cut You Up: They really would, Benitsubasa. And Kayneth even revives her after she was terminated so it would be a vivisection instead of an autopsy.
- What Measure Is a Non-Human?: Part of Meriwhether's Character Development is to accept Benitsubasa as an equal and opposing the treatment she would receive at the hands of other magi.