Second Battle of Kamejima Island

Betrayal
Shortly after the Second Assault on Tokyo Settlement Schneizel makes a plan. He will discuss a cease fire with the Black Knights and reveal to them that Zero is infact his half-brother Lelouch Vi Britannia. Negotiations go under way with council consisting of Schneizel and Cornelia on the Britannian side and with Black Knight council consisting of Toudoh, Ougi , Tamaki and Chiba (due to Zero's absence because of Nunnally's death.) Schneizel allows the meeting to go along anyway without Zero and discusses the conditions of the ceasefire. The Black Knights Agree to it which included assisting Schneizel attack Zero who reveals the catch: Zero is in fact his brother Lelouch who went missing years ago. He also reveals that Lelouch has Geass. The power to control anyone he wishes and shows known victims of Geass which included Euphemia Li Britannia, Jeremiah Gottwald, Gilbert G.P. Guilford, JLF Commander Tatewaki Katase  and lieutenant colonel Josui Kusakabe. Absolutely devastated they make their ultimatum: return Japan in exchange for assassinating Zero. Schneizel mildly shocked, agrees and they corner Lelouch in the hanger. Kallen stands in front of Lelouch to protect him and says what Schneizel said is untrue. Ougi asks Lelouch if its true And allow him to confirm the truth of his bloodline and Geass he outwardly admits its true and calls them all pawns, as they begin to shoot him. Kallen turns around and asks what he though of her. Lelouch responds as her being an important pawn in which she is emotionally ravaged and says that they can freely shoot him. However Lelouch whispers low enough for Kallen to hear to "Live On" she turns around and stares at him. Lelouch prepared to die for his sins prepares to get maimed and eradicated by bullets when Rolo in the Shinkirō stands in front of the gunfire. He pulls Lelouch inside and they escape. Rolo plans to escape Schneizels entire fleet by overusing his Geass. He is successful and destroys multiple Knightmare Frames and at least two airships. However the price is grave: by overusing his geass, Rolo's heart is taxed too greatly and succumbs to cardiac arrest.

Rise to Power
Lelouch (after much thought) plans to kill the Emperor and Destroy Britannia Himself even if it means he will die in the process. He will do this using Shinkiro only for transportation and use his Geass to force soldiers to rebel on his side and walk to the emperors location from there. He is fully aware of the Emperor's Airship being on Kamejima Island and his plans to activate Ragnarok. After preparing himself he moves out and geass many pilots, Soldiers and two whole airships crews. And Begins his venture to the island.

in the meantime Anya has been rescued by the Avalon after going through another episode in the Assault on Tokyo settlement. While resting she suffers one more before Marianne Vi Britannia takes over her body, who is discovered to be the reason for her suffering the previous three psychological episodes in an attempt to gain control over her body. She leaves in the Mordred and restores C.C's.memories before bringing her to the Thought Elevator in Kamejima and eventually the Sword of Akasha.

The Emperor on his Airship with Monica Kruszewski and an Armada; orders for a shuttle to carry him to the island with Bismark Waldstein as a bodyguard. He leaves and minutes later Geass controled rebels attack The Emperor's Airship along with the Armada. Monica gives orders to her personal Knightmare unit to retaliate and destroy all the targets. The Geassed Captain of the enemy ship gives a similar command.

Suzaku Kururugi arrives via a shuttle to kill the emperor (seeing him responsible for everything rather than lelouch). However Suzaku is unaware that the Emperor is both Immortal and has the Knight of One as a bodyguard. Bismark parries the blow and forces Suzaku to fall back (due to Suzaku's "Live" command activating.) Soon afterwards Suzaku sees Lelouch (who he feels set him up) and falls down a pit. The Emperor Orders Bismark to go to the Avalon which is coming in soon and then goes on to transport himself to the Sword of Akasha and starts Ragnarok. Lelouch arrives at the door next and enters to see The Emperor. C.C. and Marianne help Suzaku out of a pit and then get ready to go to the Thought Elevator when Lelouch (who set charges up) destroys the door to trap him and the Emperor in. By doing this Lelouch has systematically destroyed anyway of escape AND starting Ragnarok. Charles is beyond angry for his plans being prevented and instead plans to kill the gods with the Sword Of Akasha by spawning a mysterious obelisk that appears to be made of rotting animals and people.

Alone Time
During this time he knows Lelouch cannot do anything to stop him. Lelouch asks him what really happened to his mother. And the emperor prepares to explain:

It turns out Marianne had a Geass which was to transport her personality to anyone and take them over if she died. She was involved with the exact same plan V.V. and Charles wanted of killing the gods. Out of jealousy V.V. personally killed Marianne with an assault rifle. In her last moments Marianne activated her Geass and used in on a young Anya who saw the whole thing (she happened to be getting taught proper mannerisms by Marianne) and shortly after ran away. V.V. then commanded Britannian troops to set is up as a Terrorist attack and get Charles to use his Geass on Nunnally to make her believe she was blind and forget the whole incident. She then would have her legs broken by V.V. Lelouch Called this unreasonable to blame it all on V.V. and said Charles is just as much a sinner and unloving. Charles Staunchly denies this and says the whole reason for Ragnarok and killing the gods is so he can make the perfect life for his family and bring back previously dead family members. Marianne (who with the help of C.C. transports herself to the Sword of Akasha) says its true and shocks lelouch. They continue to then prove reasoning for their war against the Gods. C.C. and Suzaku then enter and begin to argue. Charles tells them time is sliping and goes on to say who god is. God is actually (in the Code Geass Universe) the combination of all life's thoughts and subconscious. Charles says he will kill it to prevent wars and conflict and make the perfect world by inserting himself and Marianne as god. Lelouch says this is Selfish and they continue to bicker. In a final chance Charles says Euphemia would want this (which angers Suzaku) and that Lelouch can have his old life back. Lelouch ultimately says no and uses his geass (which is now in both his eyes) on God to stop Ragnarok and start tomarrow. This will Kill Charles and Marianne due to the Cost of Ragnarok being everyone who started it and believe in it will die (this would not be a problem for them if the gods were dead as they could just come back) C.C. previously believed in it and instead believes in Lelouch. The Emperor then makes a futile attempt with his disintegrating body to choke Lelouch however it is too late and Lelouch's Parents die.

Elsewhere Monica Kruszewski and Schneizel El Britannia along with the Order of the Black Knights defeat the rebels and recover Anya.

Aftermath
A few months later Britannia believes the Emperor is missing. and Lelouch comes to the throne. Odysseus says this is ridiculous and tells his brother its no longer time to play and orders the guards to subdue Lelouch. Suzaku comes in and neutralizes the guards. Lelouch Declares Suzaku Knight of Zero (above Knight of One) and uses his geass to force the royal family to accept him as Emperor.

After hearing this, all Forces loyal to Cornilia and Schneizel retreat to Asia for a new plan involving F.L.E.I.J.A. and the Sky Fortress Damocles.