Lightning senses Serah cross over, but feels nothing more than vague familiarity with the soul lingering around Etro's – no, her – throne. Her sister is only a soft orb of light in this realm, but she can still imagine Serah's features, plain as day. And she can still hear the words echo in her mind, as if they were spoken just yesterday and not a hundred lifetimes ago. You deserve to be alone.
She knows now, that the Serah who appeared before her in the final days was just a fake created by Bhunivelze. But still the words weighed on her, heavier than the chains that shackled her to the divine chair. It's true that as a goddess she cannot feel, but she was human once, and just imagining, remembering, the pain was enough.
Serah's wispy voice transcends the traffic of souls between them. "Light… ning?"
Lightning pretends not to hear. Instead, she opens a rift to the realm of the living with a lazy wave of her hand.
Serah's call brings about sadness in her. She could've moved Serah's soul along immediately after it crossed through like she always did with the others. They'd already forgotten her, so there was no point in leaving time for hellos or goodbyes.
A part of her, though, wanted – needed – to know if Serah still remembered. And that need, her last real human tether, was slowly turning into regret.
Lightning never thought she'd miss being called by her birth name. But she'd lost all right to that name, and maybe even sealed her fate as Etro's successor, the moment she'd cast it away.
Lumina – no, Claire – was reborn three years ago; what felt like mere seconds to Lightning.
"Go."
She's in Serah's head. Serah hears her loud and clear.
It's been so long since Lightning has spoken aloud. Why would she? There was no one to talk to here, after all. Her voice would probably be raspy from disuse, anyway. Perhaps even crack due to the pressurized emotion in her chest.
"Claire is waiting for you… and so are the others," she continues, ignoring Serah's fruitless protests.
A simple flick of her fingers is all it takes to send Serah through. And all was quiet again, save for her own thoughts which had been reduced to a self-consoling mantra; "It had to be me, it had to be me."
They'd moved on happily in the New World she'd helped to create, with Claire filling the void she'd left behind.
Again, Lightning wonders how many more lifetimes would pass before Serah forgets her completely.
But it doesn't really matter when.
She had all the time in the world.