My kingdom was a truly wondrous place.
Nicholas sits in a chair by Reko, who stares out of the window of his hospital room every day since stabbing Felix. Nicholas could not understand what could make Reko act so violently towards the one person he seemed to protect fiercely just a week ago.
Engelard assumed it was Grayson's gift of mental torture and manipulation. The archer explained how Leon underwent a time when he was deprived of natural light and kept in a room all by himself, so he lost track of whether it was day or night and learned that he could still live without other people speaking to him or having to speak with others.
Grayson simply explained it was what all assassins had to undergo when they joined Des Kreis. Ever since knowing that, Engelard refused to join Leon as a member of Grayson's organization, and Engelard helped Leon recover from the effects of the torture, and he was almost completely back to his normal self.