 Nunnally is the only one that can see Nemo.A red, bird-like sigil lights up in Nemo's left eye when their Geass is activated.When combined with their Knightmare Frame, the "Mark Nemo", Nunnally and Nemo are unstoppable on the battlefield, since every move is known to them beforehand (however, Suzaku and Alice are shown to be able to move faster than Nemo/Nunnally can read the future).