His Other Half (KiriBaku)

It's been seven years. Seven years, and Prince Katsuki still remembers. Seven years, and he still can't forget the day he lost his other half--there one moment, gone the next, vanished like mist. It's been seven years, and Katsuki still remembers the scream that follows him in his nightmares, the desperate plea that plagues his heart. It's been seven years since the prince swore that he would never, ever, love again. Seven years since the nation's calm and adorable prince turned himself into a merciless warrior incapable of love.
But a kingdom needs a married heir, and Katsuki has postponed his coronation for far too long. Despite his tantrums and his stubborn claims, Queen Mitsuki is set on finding him a partner if it's the last the she does. She's not getting any younger, and the longer Katsuki stayed single the longer she would be forced to attend those stupidly boring meetings on--er... The longer she would fear that her nation would be left... uh... without a monarchy. Totally what she worried about.
Tensions in the palace and the kingdom are high, and now there have been reports. Rumors arise of a monster in the woods, and coupled with the prideful (and annoying) King of the Todoroki Kingdom, Prince Katsuki cannot deal with another problem.
Catch it, he says. I don't care who or how or when, just get it out of my hair.
It's been seven years. Prince Katsuki is still too heartbroken to care.