A "Nix" is a name-mix. Anyone can make a name mix for someone else or even themselves, unless the person's name you want to mix is something like "Palanodiakelissoniamallerdinodette Jones" because that name would be a bit hard to mix. If, for instance your friend was names John Dorian you could call him Jorian. A Nix doesn't have to be a Nix of a first and last name, but it could be a first and middle name, two first names or even two people's names mixed together, for instance Brangelina!
A NIX IS : Poppy Miller: Piller Margaret and Lisa: Marsa
Paula Antonia: Ponia Max Lively: Mively
Bridget Jones: Brones or even Bones!