Zack Ward in the 'zack ward christmas story' is probably the main character. He might be an actor, or just an ordinary person whose Christmas story is being told. Maybe he's known for his kindness during Christmas, or for some event that happened to him during the holiday season that makes his story interesting enough to be told.
One character could be his best friend. His best friend might have given Zack advice and support, which influenced Zack's decisions. Another could be a mentor figure, like a teacher or an older neighbor. They could have guided Zack in important matters.
Definitely not. Luther is a work of fiction. The creators crafted the story and its elements to provide viewers with an exciting and thrilling viewing experience that doesn't have a basis in reality.
Since the story is unknown to me, Zack could be a character who experiences a deep and perhaps unexpected love. Maybe he has some unique qualities that make his 'love is blind' story interesting. For example, he might be a very kind - hearted person who looks beyond the surface in relationships, but without knowing the story, this is just speculation.