In all the world, Dyster (Dyster 
) is an extremely rare gender-neutral first name. Much more prevalently, Dyster is the last name as well as the forename.
Mr, Maria, Sally, Seppo, Sonia, Carol, Karen, Peter, Robbi, Rohan, Zach, Danny, Davey, Laura, Linda, Louis, Joona, Julia, Tarja, Neale, Emily, David, Neni, Nico, Judy, Ms, Ben, Ken, Pat, Lyn, Jon, Ian, Mary, Mark, Suvi, Anna, Anne, Armi, Adam, Bert, Paul, Ruth, Lisa, Lynn, Jane, John, Henri, and Ville