Aerith was sitting at the base of the recently repaired stairs that lead up to the Bailey, waiting for Cloud. Tifa's ghost sat with her, leaning her head against Aerith's shoulder and running insubstantial fingers through Aerith's braid. Her voice was not as strong as it had been once, and Aerith knew that soon Tifa would fade away, back into the past with everyone else that had been lost, and she would be left to wait alone. But for now her friend was with her, light and her love for Cloud still tying her to the world of the living.
"He'll come." Tifa said.
Aerith smiled sadly. "I know."
They both knew that this was the last time that Tifa would be here. That it was time for her to leave. She had done what she could– more than should have been possible, trying to heal Cloud's heart even after her own had stopped beating –and it would have to be enough. It was up to Aerith now.
Tifa smiled, and Aerith felt her wistful happiness. "I loved him." Tifa wrapped her arms around her knees and rocked back, her eyes pointed up towards the stars and Aerith knew she was remembering promises made under them, back before they understood that there are some things no one can protect you from. "You'll take care of him." Tifa said, her voice sure.
"Yes." Aerith's eyes welled with tears. She let them fall.
"And you'll be happy, together. Even without us." Tifa's own eyes teared but she kept going. "You'll be happy, and we'll be waiting for you, so you better have some good stories for us!"
Aerith wanted to touch Tifa, to link their fingers and put her arm around her like she had been able to what felt like ages ago. "We will."
The whisper of a kiss across her brow, the scent of high mountains and flowers that flourish there against all odds. "I loved you, too."
And then she was alone.
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Author's Note: I read in an interview with Nomura, I think it was, that Tifa did not necessarily exist as a person, but was just a physical representation of Cloud's light as Sephiroth was his darkness, and that's why she only interacts with Sora and Cloud. Or she can be a resident of Radiant Garden. That you can take it either way. And… this popped into my head.