Maut

You are foolish to think you can defeat me. I am the embodiment of all evil, and I am unstoppable. You are doomed, boy. Your death is only a matter of time.

— Maut, to the Champion of Hylian.

Known by many names, Maut is a dark entity, a direct refraction of the Golden Gods. Where the Gods create, nurture, and lead Hyrule and the greater creation as a whole, Maut seeks to destroy it. His goal is not possession, victory, or to torment, but solely destruction for its own twisted sake.
For a thousand years, Maut was sealed away by the goddess Hylia and her Champion. Hylian went on to have her being reincarnated in the bloodline of Hylian women, ensuring that she would be ready to seal the Demon King away. When Maut did manage a near escape thanks to his follower, Ghirahim, Hylian and a new Champion would rise to ensure Maut's further imprisonment, and eventually destroy Mauts physical manifestation. Drawing upon his dark magics, Maut cursed this Champion, his soul to forever be reincarnated alongside his so they could do battle until Mauts victory.