Enraged, Lelouch orders the Black Knights to launch their surprise attack- and with the support of the Chinese Army, which has allied itself with Zero. It becomes a four way slaughter between the four forces, but the Black Knights do not engage in much actual combat- merely protecting themselves. They allow Schneizel's forces, the Emperor's forces, and the Chinese forces to slaughter each other. The Black Knights then pick off the survivors.
Then, Lelouch rakes the Avalon's engines with the Gawain's hadron cannons. With its float system powered down, the floating battleship crashes onto the Britannian capital, almost obliterating the palace.
Within the palace, the Emperor struggles out of the debree. Zero stalks through the flames, cape billowing behind him. Lelouch removes his mask and demands that his father tell him why he killed his mother. Laughing, the Emperor responds, "To make you what you have now become!" He then begins to cough, and Lelouch draws back, horrified, as the Emperor congratulates Lelouch for winning the game.
Then, the Lancelot appears and demolishes the Gawain. The Guren Nishiki interjects, and the two mechs fight until both are no longer operational. Suzaku drives one of Lancelot's swords into the Guren's cockpit, which uses up the last of Lancelot's power.
Coming out of the cockpit, Suzaku levels his pistol at Lelouch and says that he will now, at last, bring an end to the carnage Lelouch has visited upon the world. Just then, the Emperor rises to kneeling behind Lelouch- and at the same moment, Britannian soldiers burst into the ruined throne room.