Imagining a world without go and what it must have been like for Sai... I feel like crying...

Hmm... Slightly depressing. Feels more like the intro to a story than the story itself.
I can't help speculating on who or what woke Sai up. Obviously Vara, since she can see Sai. Maybe she (and Sai) would be the catalysts to reawaken Go in this world, since ancient times are still remembered, however distantly.
Just a thought and a note, to paraphrase, "Just because you don't believe in God, doesn't mean she doesn't believe in you." (Yeah, I'm a glass-half-full person)

Thanks for the story.
(PS: your disclaimer and intro are swapped)

Poor, poor Sai... that is really Hell for him. Yes, of course I'd be curious to see what would happen to him next, but can't be helped... I'm just happy you wrote at least this much. A chilling what-if, truly.