The first half of the eleventh Yongsa Pati Ttaelyeochiubnida novel concludes the long-running Kyle/Raniel arc that began in the first (rather than the series as a whole). The second half then picks up after a 3-year timeskip to center on bringing the fight into the demon lord’s territory, with a greater focus on Raniel’s former students.
Aku no Reijou to Juuni no Hitomi (English subtitle: The Legendary Villainess and Her Elite Assassins) has a slightly misleading English title (she’s a duke’s daughter rather than a princess) and starts off with that standard villainess scenario of ‘crown prince fiancé getting stolen by a light magic user’. The twist here though is that there is no twist, with the villainess being actually villainous and wholly guilty of her crimes.
The actual twist is that she gets a second chance anyway and through the power of misunderstandings similar to those found in Monster no Niku (a work by the same author) becomes something resembling a good person. Although the first third is rough, it picks up nicely after that and remains entertaining up to the pair of endings, where a second twist comes out of nowhere.