[Meophist]

I gathered as much as I can on Dark Nanoha but there still seems to be some missing. Most of this is by Dragnfly@Gamefaqs.

Spoiler for Dark Nanoha:

1) Dark Nanoha lives in the same house as Nanoha.
2) Dark Nanoha showers with the lights off.
3) Dark Nanoha mixes fish oil, orange juice and milk for her morning drink.
4) Fate is afraid of Dark Nanoha but plays with her regardless. She's brave.
5) Nobody in Nanoha's family notices a difference except for her sister. So far she's failed to convince the rest of the family that anything strange is going on.
6) When Vita got Dark Nanoha's name wrong, DN headbutted her 26 times.
7) She eats her food live
7) Dark Nanoha's transformation scene was written by the guy who did Genocyber.
8) Yuuno still hangs out with Dark Nanoha, despite mainly being target practice.
9) Dark Nanoha puts more sugar in her tea than Lindy does. However, she doesn't seem hyper.
10) When eating cereal, Dark Nanoha stirs it around for immense periods of time, never taking her eyes off your's.
11) Dark Nanoha likes to hide in lockers. When somebody opens it she giggles and asks if they want to come inside too.
12) Dark Nanoha is banned from the town of Silent Hill for inexcusable behaviour.
13) When Dark Nanoha saw Ringu, she crawled INTO the TV and killed Sadako.
14) Dark Nanoha held Raging Hate to the animator's crotches until they agreed to work on a new series.
15) The animators thought she was bluffing, but went right to work when she said "Starlight brea..."
16)Dark Nanoha is the creator of the infamous Nanofei doujin and the 3D game
17) Dark Nanoha was removed from her role in the Higurashi anime because her suggestions were far too brutal for the series to depict.
18) Dark Nanoha is the main reason why Waita Uziga started his career as a Guro Mangaka.

28) When Nanoha and Vita were both entered the Ashura Croquet Tournament, Dark Nanoha suddenly appeared over the tournament sign and moved a part of the sign, revealing the words "extreme full contact".
29) While playing minigolf, Vita was suprised when Dark Nanoha spiralled out of hole #18 like some hellish serpent, Mountain Dew spewing from her nose and ears. She asked Vita if she thought James Earl Jones had a sexy voice, then went back into the hole.
30) That course is now deemed "condemned". Dark Nanoha appeared over the sign and moved a part of it, revealing the words "to HELL!!!". It must be one of her powers.
31) It's not that Dark Nanoha takes medication for her mental illnesses. Some think it's the medication that made her that way.
32) At a family BBQ, Dark Nanoha prepared a deliscious dish. When asked what it was, she grinned and held up a picture of a Prinny.
33) While in Silent Hill, Dark Nanoha did some act which was constantly censored. Note that this is NOT the act that got her banned from the town.

42) Dark Nanoha is also aged up for StrikerS. But she's at that creppy age where you can't tell if hitting on her would land you in jail or not.
43) For her sweet 16, Nanoha got a nice car. But Dark Nanoha secretly replaced the ignition with the activation trigger for the Arc en Ciel. Let's see if she notices.

45) She whispers strange words into your heart and makes your paranoid days.
46) Don't think Dark Nanoha is exempt from StrikerS. She's assigned to an office under the Ashura's engine room. Few people go near there but those who do say they hear weird sounds at night. Heck, they hear them during the day too. Wait. This is space! It doesn't matter!
47) Dark Nanoha was in Shadow of the Collosus for a bit. She fought one of them but the screen just went black, only to return moments later with collosus guts everywhere and her giggling. Any who heard the audio from that no-video scene have been turned over to an insane asylum.

50) Nanoha befriends her enemies. Dark Nanoha drinks them alive.