Looking at how Arnold was rather unharmed, yet surrendered without putting on much of a fight.
Keith's claws dug deep on the ground, growling, as the pain and sorrow was too much for him to speak.
Though, as powerful as he was, he didn't want to go through the deeds enough to dirty his hands.
Ever since Mystique's tragedy, he has changed. Even hearing him so graceful and honorable enough to give up all of his assets and properties as her sole daughter's utmost recovery was paramount.
Arnold lived a quiet lifestyle, slipping out and away from the other noble affairs while still upholding his responsibilities as the protector of the north.
Even after she recovered through a miracle, Arnold still kept his word, regardless of the unknown benefactor. The news was no longer a secret, and perhaps living the rest of his life to a better outlook in life was much better than all the prestige.