Hametsu End Kara Gyakkoushitara, Nishuume wa Nazeka Aisare Route Deshita: Yami Ochi Reijou wa Ouji e no Fukushuu wo Akiramenai (no ni Dekiaisareru)

Lilith, a duchess, is falsely accused by the Saintess, and then imprisoned and executed by her former fiancé, the crown prince. She finds herself reborn back in time to when she was ten years old. She swears revenge against her fiancé and those who betrayed her, but there is something different about the prince in her second life, as even the people around them are surprised at how sweet and doting he is acting towards her this time. But it's too late to be nice now. She's going to take revenge on him! It's not love that's making her heart beat faster when he comes on to her! It's her desire to kill!

(Source: Futabanet, translated)