I have just finished reviewing Code Geass R1. It really is the king of detailed symbolism. Let me present to you this part in Episode 25.
When Villeta and Ohgi were talking in Ashford Academy, we get this screen shot of two paper cranes- black and white. They're facing each other like two sides of a chess board. As we all know, chess is a recurring theme in the whole series. We can assume that the white represents Britannia and the black, the titular Black Knights.
After Villeta shot Ohgi, we are brought back to this same frame again. Only with the black paper crane fallen off balance- signifying that the Black Knights will lose the Battle for Tokyo.
There's also another interesting thing I've noticed in this scene- the use of papercranes. In the series, we see Nunnally continuously making them because she wanted to make a thousand for her wish to come true.
Hear me out, Lelouch left the battle in order to rescue Nunnally in Kaminejima. She was kidnapped by V.V. (but at least at that time, Lelouch did not know V.V. ) We can infer that Nunnally is a major cogwheel of the battle. Without her, the Black Knights wouldn't even have been created in the first place. So the use of papercranes created by Nunnally is pretty symbolic for cluing in the outcome of the fight which, in the first place, started because of her.