Code Geass: Lelouch of the Rebellion R2

[Ryllharu]

Only if the Geass works exactly the same way Lelouch's does, damaging (or rewiring) the brain as it works, then it might be possible to become "immune."

We already know that multiple memory-style Geass abilities can be used on the same person. Lelouch himself. He Geassed himself during his final encounter with Mao in order to protect his plan involving Suzaku saving Nunnally and then rescuing Lelouch. Lelouch couldn't remember his own plan or Mao would have seen through Lelouch's acting. Then the Emperor overwrote Lelouch's memories when Suzaku dragged him before the Emperor.

So it's still very possible that Kallen could get brain-wiped Total Recall style.

There are only two (maybe three now) people we've met who are immune to Geass abilities. C.C., V.V. and perhaps now Orange-kun. They all grant the Geass abilities (or are synthetic copies of those who do), and cannot be affected.

EDIT:

@Kraco:

I would love to see an elaborate plotline where Kallen "escaped" in some amazing fashion, only to entrench herself as a spy. Cliche, sure, but still fun. There would be little way for Lelouch to know that she was lying, and since he long ago used the Geass on her, he could not check to see if she had been turned. Then we might have a long, drawn out, cat-and-mouse game like we were all hoping to see with Rollo and Viletta vs. Lelouch.

Still, I think that if anything, it is more likely Suzaku would return her to that Academy as a brainwashed Kallen Stadfeldt. Despite Rivalz, Shirley and Milly knowing that she was an open member of the Black Knights. Suzaku would be that much of an asshole if the Emperor went along with it.