lelouch sacrifices himself for the world by strategically placing all the hatred in the world onto himself and then having his best friend and knight suzaku publicly assassinate him, ending the chain of hatred.
after his death he hugs suzaku and tells him that this is now his punishment. he has killed his best friend and now suzaku is dead figuratively. he will live on as a symbol "Zero."
His body tumbles down the front of the float. at the bottom his sister, nunnally, waits. with a touch she sees what lelouchs true objective was and that he wasnt the "demon emperor" he made everyone perceive him as.
with this knowledge she earnestly tells lelouch that she loved him and that she just wants to live in a world with him. lelouch replys with his dying words, "i destroy worlds and create anew."
with this he dies finally. the shout "the demon emperor lelouch is dead" rings throughout the parade grounds.
the crowd chants Zero's name as nunnally weeps and screams over her brothers corpse.