i think that is lulu at ending that 1

Biggest Clue;Paper crane:Nunnally taught Lulu to made those in R1

Lelouch is still alive. He has Charles’ Code which he received when the man choked him. The Code activates first when you die, which happened. Charles code got activate when he shot himself the first time, same with C.C. when she was killed by the nun. And before you say can’t have Code and a Geass at the same time, the Code wasn’t the one C.C. had, meaning that Lelouch was the first one to achieve Code Geass. Lelouch’s code also activates when Suzaku stabbed him. Nunnally even gets ‘memory watch’ when he touched Lelouch. It was the similar effects when Leluch touched C.C.’s body back in the cave episode. This pretty much tells us that he really has the code and it is activating to revive him. He’s now traveling the country-side with C.C., living as immortals.

That’s the only reason for C.C. to be suddenly so happy again. Also, before you say that C.C. was just talking to the dead like with Marianne, that’s not true. She could only talk to her because of the nature of her Geass which allowed her to implant herself into the “hearts” of others. That’s how she was able to talk with Marianne. Lelouch’s Geass was entirely different, meaning that she could only have spoken to her if he was there.