In the Manga when the three Links rescue Violet Link. They really come together for the first time. Realizing how much they need each other, they combine the powers of the Four Swords and mop the floor with Shadow Link... at least for a while.
When Shadow Link uses the last of his strength to destroy the Dark Mirror. He comes through for everyone in the end.
Shadow: I came out of the Dark Mirror, and with its power woke you. How fitting that I use it to destroy us both!