Crystal, Lelouch and the other Black Knights were on a mission to find the four witches and get the four magical gems in order to beat Dark Star, a powerful sorceress. As the battle went on with with the first witch Malaranea...she appeared to be too powerful. Lelouch took his wife, Crystal and they hid behind a wall, then he turns her to face him.

"Crystal, my love...I'm sorry for this, but I can't risk you getting hurt here...look into my eyes..."

Lelouch says as he activated his geass in his eyes, he was attempting to put Crystal unconscious for the Time being until the battle is over.