Power is a major theme. Two Lucifers would bring a lot of power into one story, and it can be about who has more power or how they use their power together.
In the world of 'lucifer meets lucifer fanfiction', a common plot could involve a clash of egos. When two such powerful and complex characters meet, there's bound to be conflict. Some stories may also explore a romantic or at least a deeply emotional connection between them, as they are essentially the same being in different forms, and this connection can be both fascinating and disturbing at the same time.
Linda Jones could be an author, a character, or someone related to the Fantastic Fiction world. Without more context, it's hard to be specific. Maybe she's an emerging writer who has made a mark in the Fantastic Fiction genre with her unique stories.