I spent Day 1 of NaNoWriMo just reading my story Nerima All-Stars. It's some 150,000 words long. The file is actually 177,000 words long, after I deleted some stuff, but this also includes a lot of research.
Things included in my research:
1. An incomplete List of Heroes and Villains and their abilities
2. An incomplete List of Gods and Goddesses used in the story.
3. Magical Girl Spells
4. "Regular" Magic Spells (pulled from Ah! My Goddess and Slayers)
5. Magical Instruments Made of Bone. (includes Maui's bone fish hook; the first kantele made by Väinämöinen; the magical harp in the Cruel Sisters / Twa Sisters ballad (I added names to everyone); and a reference to Sampson, who slew a thousand men with the jawbone of an ass. In my story, this was actually a magical weapon made of bone. ^_^
6. The Doublet System in Ah! My Goddess explained
7. Notes on Hawaiian Pidgen.
8. Notes on how the Japanese government is structured and run and where it is located.
9. TV Tropes article on Heroes vs. Villains
10. Notes about the Völva, the Norse witch, and the song Allison Gross.
*******************************SPOILERS************************************
Note that I am providing spoilers to a story that nobody has been allowed to read yet. :P
At this point in my story, here is what has happened:
Thor, Urd, Skuld and Belldandy agree to a game with Loki Odinsson and Mara (a demon).
As a result, Ranma, Akane and the cast of Ranma 1/2 wind up in a superhero world overnight.
The god/goddess team pick four champions to become heroes, while Loki and Mara choose a suitable villain. Early chapters involve training, but Loki cheats to get his villain up to speed. Because of course he does.
Doctor Pineapple soon has all of Nerima under mind control, and that includes some of our heroes, and some other prominent heroes. There's a fight, and the heroes manage to rescue their friends and escape.
At this point in the story, Urd, Skuld, Belldandy, and Thor decide to break the rules a little bit too. Urd sends Ranma to the world of Slayers for ten years, and then returns him to Nerima just minutes after he left. He's now a very skilled sorcerer. The others send their charges away as well, allowing them to become highly skilled in mere moments.
All of this takes multiple chapters to detail, but finally we are all back where we were: heroes holed up in a secret base, ready to fight Doctor Pineapple again, and much better prepared.
However, by this point other demons have taken an interest in what's going on, and Doctor Pineapple is able to trap the heroes in time for three months while his plan to take over Japan succeeds.
This is pretty much where I'd written to by the end of NaNoWriMo last year. I had "several big fights and a final showdown" planned, but not really planned. I hadn't really worked through what the villain would do, and how the heroes would respond.
To start with, Doctor Pineapple has three months to plan and knows when the heroes will be released from their time trap. It would make sense to attack them immediately, before they have a chance to orient themselves. However, many of his allies are mind-controlled heroes, and he can't send them against the heroes as long as those magical girls are able to break his enchantments. So he'll want to assassinate the magical girls if he can, and/or send in only those who are willing allies, and those who he doesn't care about losing (lots of minions).
IE I'm still at the planning stage. ^_^ I've written about 1,300 words so far today in working out my plans, however.
