Beating Null in Zelda: Echoes of Wisdom is the final part of the main story quest 'The Prime Energy and Null' and Null's Body dungeon which you will need to complete to finally save Hyrule.

The final part of The Legend of Zelda: Echoes of Wisdom is a face-off against the big bad behind it all, Null. After venturing into the Stilled Ancient Ruins, you’ll hit the point of no return ...