She knew that no matter how far they traveled they would never find a way out of this chamber. Killing this other Link was not an option, normally she would not have thought twice, but she knew he was special. She didn't quite know why he was special but something told her killing him to get herself out of here would come back to hurt her eventually.
"I've got it!" she exclaimed, other Link remained expressionless as usual. "How could I be so stupid? It should have been obvious from the moment I met you that you were my ticket out."
Yet, you do not mean to kill me? You must know something I do not.
"Of course I'm not going to kill you." she replied with a wink and a tap on the very tip of his nose. She noticed the faintest trace of a smile. "Good to know he can show some emotion, maybe he is Hylian after all." She thought.
"I believe that I got in here because I sensed and subsequently latched onto your presence, brining me here. My theory is that I can do it again, though I will seek Link's presence rather than yours. Hopefully I'll be able to find it and get us out of here. I also believe if you hold onto me as I leave you will be transported with me."
Are you certain you want me to come? It sounds as though my presence may be detrimental to your escape.
"Don't worry about me pretty boy, I've been dragging your twin out there around for a while, I can handle you."
With that he held out his hands palms facing her, she put her tiny palms flat against his. Their fingers intertwined as she shut her eyes and began to stretch out her senses searching for Link.
"Ah! I think… I think I found him, hold on!"
The now familiar bright white light again obscured her vision. For a moment she panicked not being able to see her companion, but she felt his fingers squeeze her hand and she was reassured that he was not only still there, but was also making through this process.
Then the light began to fade and she could see again. They were in what seemed to be an underground lake, there were stone walls all around and as they descended a beige sandy bottom littered with plants and broken monuments became clearer. Admiring the cavern they were submerged in she remained completely oblivious to the plight of both Links until she saw a monstrous creature swim by, with a small form latched onto it's back. Link seemed to be handling himself, it was the other Link who she had to worry about. She noticed him struggling to breathe. Damn it! She had forgotten that he wasn't a spirit and needed to breathe, and unlike the Link zooming about on a sea creature right now, he did not have the Zora's Armor that allowed him to do so underwater.
Using her magic she summoned her remaining power into her hair, forming it into a large hand. Grabbing onto his waist she began to push upwards through the water hoping to reach the surface before it was too late. She didn't waste most of her energy getting him out of that purgatory just to let him die in this hellish place.
She was soon able to see the surface of the water, and even though she was tired she seemed to be moving closer to it at a much faster rate than she had moments before. Lifting the other Link above her head she allowed him to surface first, following herself moments later. He seemed to be unconscious but still breathing.
"Good to know all of my trouble wasn't for nothing." She muttered to herself.
Then she noticed that she was falling. Well she wasn't falling but the water level was swiftly dropping, lowering them the entire way down to the sandy basin. Once on the flat ground she laid her burden on the soft ground. She quickly made sure he had survived the ordeal and once she was certain she drifted over to Link himself. He was standing there proudly holding the last fused shadow, seeing her he smiled. Presenting her with the fused shadow he nodded, ready to resume their journey apparently unaware of the guest she had brought along with her.
"Alright back to Lanayru!" she said.
Link nodded his approval again. She created a portal to take the two of them back to the light spirit. With the very last reserves of her energy she created one final portal underneath the body of the other Link, she watched him be carried up into the portal just as her body began to break apart and do the same.