This is just a very brief overview of the key facts about this character.

His name isn't important and could easily be changed. What's important here is that Storm was a soldier in the zebra war and at some point he stumbled across Celestia's old journal from when she was very young. It tells some specific facts about the wild alicorns that led Storm to believe Nyx had the capacity to end the zebra war once and for all. He simply had to convince her to embrace the transformation she was undergoing, rather than avoid it as Luna advised.

This presents a significant plot twist in Black Feather because Nyx now has valid reasons to either embrace or avoid her transformation. She doesn't know who to believe because Storm is a trusted friend, an employee at Twilight's science institute, in fact. There's a chapter later in Black Feather where Nyx is helping Storm with something technical and the two of them have a talk. He reveals the journal to Nyx, and this puts everything the alicorn sisters have told her into doubt.

Importantly, Storm is highly motivated for Nyx to forcibly end the war, preferably with as much death and destruction on the zebra side as possible. Why? Because Storm's daughter, Misty, was killed in the school tragedy referenced many places in the story. You can read Misty's story that I wrote before we broke off from Fallout: Equestria. Look for my story titled Littlehorn and you'll see exactly what happened to Storm's daughter. This is why Nyx was so emotional in chapter five of Black Feather when she was in her bedroom alone, looking at the drawing Misty had made, which she keeps in her nightstand.

All of this is a deeply emotional thread for Nyx in Black Feather, and Storm's connection to it is an important aspect of the story. He's not a bad guy, truly... he's just grief stricken because of the horrific death of his daughter and he believes Nyx can avenge her or at the very least potently and decisively end the war herself if she becomes nearly omnipotent. Important also is the fact that Storm is unaware of the morality changes an alicorn goes through when they fully mature. This is why Celestia and Luna have forsaken their own transformations and instead allied with the mortal ponies.

There is much more I could say about the intricacies of Black Feather's plot, but these facts specifically I needed to post now as a matter of public record, as I intend to use this character in my non-MLP published version of Black Feather.