Majora’s Mask
To start this fight talk to the kid under the tree wearing Majora’s Mask. If you did all the areas here he will give you the Fierce Deity Mask. You didn’t do those areas he will way your masks are weak. In here if you don’t have the Deity Mask just shoot light arrows into it’s back. When he gets into the phase where he has tendrils just slash those. Repeat until you have won. But If you have the Fierce Deity, just use your laser beams to win. Nice you have defeated the terror of Termina, while helping a lot of people.