Too bad her recurring illness keeps her out of school so often.
(The illness is called Secretly A Member Of The Resistance.)
Mind control let's you skip the dance and just confirm that she's the same Knightmare pilot.
But when he tries to keep her silent, it doesn't take.
Here's Lelouch's younger sister Nunnaly, who is a blind and wheelchair-bound.
If you had to ask why Lelouch hates the empire, what happened to his sister is a good start.
Lelouch tests his power. The limit is: he can only use it once per person.