Armed Resistance

Armed Resistance is a Code Geass Fanfic, specifically of the Alternate Universe Fic variety.

The story starts off with 17 year old Lelouch Gaspar, an alternate reality version of Code Geass character Lelouch Lamperouge. For the most part, they are the same- the only differences are that Nunnally, Lelouch's sister whom he loved and thought the world of, is dead. There are some significant changes to the universe's background, as well. From there, the changes begin to snowball- the slight differences in how Gaspar behaves slowly derail the series, adding new elements, changing plot points, and so on.

This series is not yet completed.

Tropes used in Armed Resistance include:

Alternate Character Interpretation: The Emperor, Lelouch, Shirley, Suzaku, and more. Much of the cast.
Airstrip One: The Britannian system of Areas
Alternate History: Actually an alternate history of Code Geass's alternate history... so an alternate alternate history.
America Takes Over the World: Actually Britannia (England), but same idea.
Anime Hair: C.C, Shirley, Karen, Jeremiah Gottwald, and a few others.
Anti-Hero: Lelouch Gaspar, to the extreme.
Big Damn Heroes: Directly quoted in chapter 20, with Lelouch and ~~Kallen~~ Karen at Narita. Lelouch is ecstatic about it, sporting a wild grin while invoking the trope.
Big Screwed-Up Family: The Imperial Family, very very much so.
Black and Gray Morality: The evil empire of Britannia versus the complete bastard Lelouch.
Bodyguard Crush: Suzaku and Euphemia, Lelouch and Karen.
Chainsaw Good: The Gurasugo's chainsaw bayonet.
Grey and Gray Morality: Basically the point of the whole story, as well as Lelouch Gaspar's life philosophy.
Last-Name Basis: How the author refers to the main character.
Magnificent Bastard: Lelouch's defining characteristic.
My Hero Zero: Lelouch's alternate identity is named Zero.
Pet the Dog: The (ultimately) sympathetic treatment of Mao, especially concerning C.C.
Red Baron: Quebec (Karen), India Foxtrot (Shirley), and counting....
Shipper on Deck: Shirley, shipping Lelouch/Karen.
Spell My Name with an "S": In the early days of Code Geass, the romanization of Kallen's name was uncertain- there was some debate over whether it was supposed to be "Kallen" or "Karen." The debate was settled- it's Kallen. The author insists on using Karen, however.