Fanfic: The Path They Travel (by azurefishnets)
Found on Archive of Our Own. About a 10 minute read.
Their description of the story:
A brief stop in their journey through the Serpent Trench gives Cyan, Gau, and Sabin a moment to learn a little more about each other.
The author really highlights some of the similarities between Sabin and Cyan that they themselves are just learning about.
I think it's fair to say that the game glosses over the trauma and grief that Cyan must be going through, having just seen his family and entire kingdom killed, then watching them get whisked away to the afterlife on a train that frankly is full of really sketchy spirits. It could be understandable to see why Cyan feels very isolated in his pain.
I also love stories where Sabin is shown as having more depth and maturity to him than is portrayed in-game. Thinking that he places a lot of importance on tea is a wonderful contrast to the frantic glutton he acts on the Phantom Train, but it still feels right for his character.
Gau is also shown to have more insight and heart than is usually portrayed in-game. It makes sense for him to have an naturalistic understanding of living creatures, even if he can't communicate it very well.
Finally, I love the idea of Duncan's wife smacking Sabin regularly for being a smart-ass. Weirdly seems to parallel Yang and his wife from FF4.