@storyyeller
Let's see:
He deduced who Lelouch was due to how he played chess. Figured that he was somehow connected to Suzaku based on their childhood and how oddly the two acted when they were around each other. He had his men trail Suzaku and through this he was able to find Lelouch when Lulu went to speak with Suzaku at the temple. He recorded the entire cnversation that the two had and after Lelouch escaped, Schneizel manipulated Suzaku into telling him everything about Geass. (including Suzaku's own LIVE order that forces him to do anything to save himself if his life is in danger)
He then had a nuke (which he manipulated Nina into making by playing off her loyalty to Euphemia.) grafted onto Suzaku's Lancelot, knowing that the oncoming battle with Lelouch would put Suzaku in a position where either he'd use it willingly, or his LIVE order would force him to use it in order to survive. (or they win the battle without needing to use it. Win-win)
He had Lelouch's sister evacuated during the battle using a hidden plane. but since Lulu didn't know about that, he assumed his sister was killed in the explosion. Schneizel knew about Lulu's utter DEVOTION to his sister, and how the thought that he'd lost her would drive him into insane depression. He used this period after the battle to arrange a meeting with Lelouch's Army, (knowing that Lulu himself would be too traumatized to make an appearance) and manipulate all of them against their leader (using the recorded conversation from earlier)
He had Lulu's men lure Lulu into an ambush. Only a timely assist from Rolo (whom he had NO idea was going to help him) managed to save him.
Even after all that, he still had Nunally, whom Lelouch still thought was dead, and used the revelation that she was still alive to rattle Lelouch's mind and stop him from making rational strategic plans.
GASP (collapse)
"Peace is an illusion, to turn illusion into reality is an arduous task. It requires discipline." - Schneizel El Britannia