Unnamed Memory, Vol. 5 (light novel)

"The end of the curse ... Fifteen years ago, Oscar was cursed by the Witch of Silence to never sire children, seemingly dooming the Farsas royal family line. And though Tinasha finally succeeds in ending the wicked enchantment, there is little time to celebrate, as one incident crops up after another. In the midst of it all, the Witch of Silence makes her move. No one has ever known why the powerful woman cursed Oscar, and the truth is more shocking than anyone could have realized.