Youjo Senki  

Saga of Tanya the Evil, Yôjo Senki: Saga of Tanya the Evil, 유녀전기, 幼女战记, 幼女戦記, The Saga of Tanya the Evil, The Military Chronicles of a Little Girl

Tanya Degurechaff is a young soldier known for her ruthless tactics and exceptional strategic skills, earning her the nickname "Devil of the Rhine." Despite appearing innocent, she possesses the soul of a man who once challenged Being X, a self-proclaimed god, to a battle of wits. This challenge resulted in her being reincarnated as a little girl into a world of magical warfare. Determined to defy authority, Tanya aims to rise through the ranks of her country's military as it descends into global conflict. The only obstacle standing in her way is Being X, who remains the strongest force. However, her keen actions and combat prowess have an unintended consequence: propelling the powerful Empire into one of the most dominant nations on Earth.