Just realized something.
Lerouch is one of the few "used correctly, can kill a Saiyajin/Saiyan of
Dragonball Z/Kai "
normal human characters.
Even if the Geass does not work on full blooded Saiyajin Warriors like Prince Vegeta or Kakarot, Son Gohan, Trunks and Son Goten (and of course, Gotenks) are still
half-human.
And
no human, no matter how strong willed, can resist even the
kill yourself command.
Oh, Lerouch, you scare me more and more every-day.