After the Princess Was Reborn, She Went on a Killing Spree!

Overhead era! The four kingdoms are standing in a tripartite state, and there are constant disputes. Why not unify the world? A growing heroine! After rebirth, there are still many difficulties. How to take revenge? How to protect others? In the process, the heroine relies on her strong perseverance to keep moving forward? The heroine is beautiful and strong, she is cruel in the early stage, but sweet in the end!