My turn right? Okay,
Game: Majora's Mask
Subject: enemy
Round in shape, I bear a strong resemblence to one of Termina's races
Attack me or not I am certain to die
Game: Twilight Princess
Category: Enemy
You shall find me at three sacred places.
I bear a resemblance to one of Hyrule's races.
Under a cave with ordeals to face.
You must defeat me to leave this place.
Okay then:
Game: Wind Waker
Subject: Character Day and night I stand in one place I used to enjoy watching the tower bringing light with my secret somebody
It... isn't Kamo, is it? The depressed dude on Windfall (with the windmill/lighthouse, the tower that brings light) who sits on the steps night and day.
EDIT: Wait, he moves to the bridge at night. Darn.