Being in control means wielding the knight. Wielding the knight doesn't require weakness, so her weakness is irrelevant. Being in control means not tormenting the Maid. A grip on this sword requires the illusion of kindness and that means she cannot punish her tame, fearful devil-king. Not yet. So she smiles down at her, and only from the Maid's angle can the glittering savagery be seen in that smile, even as she speaks for the Knight's benefit.

"Oh, noble knight, thank you for rescuing her for me," said Fengye, not breaking eye contact with her Maid even as her voice quavered with crocodile innocence. "Please protect us both!"