"No."
Raiden blinked, tender lips parting ever-so-slightly as she processed the forbidden word. Stunned into silence, she remained still as a statue, revealing nothing of the storm brewing within.
"I've never been one to stay in the same place for long, Raiden, and now, even less so. You know why I can't stay."
He was right - she did know why.
She, like Barbatos and Morax before her, couldn't speak of the happenings of five hundred years ago, only barely refraining from overstepping her authority by pointing the Traveler in the direction of Sumeru.
"Your sister." she whispered, somehow withholding the intense, irrational loathing that manifested at the mere thought of the girl.
The Traveler nodded, facing the stars with a distant, wistful expression on his face.
"Home is wherever we are together… that's how it's always been."
She couldn't say whether it was his words or the way in which they were spoken, devotedly and laced with longing, but Raiden saw red, sent over the edge as she leapt towards him, pinning him roughly against the ground.
If anyone had ever refused her before, it'd been so long ago that no memory of it remained.
"Is that so?" she hissed, venom coating her tongue. A flash of fear crossed the Traveler's eyes, and curiously, Raiden felt both horror and satisfaction at the sight.
"I could simply keep you here, Aether. God or not, I am still lightning, the rain transformed, and there is nowhere in this world that you can hide from me."
Fear gave way to steel, and the Traveler glared up at her defiantly.
"If you do, I'll never forgive you."
She laughed, the sound unfamiliar even to her, and carrying enough coldness to send a shudder down the slender frame of her prey. Forgiveness was already beyond her, and one additional crime mattered little.
It would be worth it, if only to be able to see him each day.
As though mirroring her thoughts, the sky darkened, and murky, stormy clouds gathered overhead. Tiny droplets of rain splashed against the Traveler's face, trickling down his cheek in a manner akin to tears.
"Ei…" the Traveler began, and like each time he spoke, her conviction wavered.
The sound of her own name, forgotten to all but a select few, caused her to deflate. The rain, however, did not cease, and instead the clouds grew to paint the sky a solemn grey.
"Why?!" she cried, throwing her head back in anguish. "Why must I be cursed to lose all that I hold dear in this wretched world?!"
"Ei." he repeated, his tone imploring her to meet his eyes.
Raiden - or perhaps it was Ei - did so hesitantly, afraid and uncertain, dreading to see the care and kindness she desired replaced with contempt.
Her breath hitched, a lump forming in her throat. The Traveler looked at her with understanding, revealing a compassion so deep that she momentarily forgot her own pain, imagining what kind of suffering could yield such empathy.
"I know."
She believed him.
"We'll find a way." he said, and still, for some reason, she believed him. "Once I reach the end of my journey, then-"
"What then?" she breathed, her face inches from his, her body enveloping him even now.
"I suppose… It's something we've never done before, but… you could come with us."
When the reality of his offer became clear to her, Raiden gasped. A ray of light pierced the heavens, the sliver of hope she felt made visible, and the more she pondered it, the more appealing it became.
The Traveler could never remain at her side, and verily, for the sins she'd committed, such a blessing was much too gracious for her.
Raiden could, however, remain at his.
She would stand beside him, hand in hand as they stepped foot on countless, untold worlds, and each night, bathed in starlight, she would braid his hair, caress him and care for him, and never again would either of them grow lonely.
This, the Raiden Shogun promised - the last promise she would ever make.
Forever and ever, until the end of time itself.