I recommend the book, The King's Conspiracy. Although the male protagonist was not ambushed by a voodoo, the female protagonist had a plot of changing blood to save people. Moreover, it was a story of becoming powerful after transmigrating and reincarnating, defeating enemies and sitting on the throne. The male lead had a strong sense of existence, but if he couldn't win, the female lead would get jealous. I hope you like my recommendation, Mwah~