As others have suggested, you can use a thought form. One phrase people are starting to use is called pop culture practice (or pop culture paganism). It is where one uses a fictional archetype in worship and practice. It isn't widely accepted, but it also isn't something that is considered 'fluffy'.
An example would be using Marvel Loki as an archetype to worship instead of using the historically religious form or even using Marvel Loki's image to worship the historically religious form. Loki tends to be a God that wouldn't mind that as much as someone who is a complete no-nonsense personality.
Point being is that you can worship a fictional archetype if you'd like to. Just be sure that it is something that you don't take lightly and is something you seriously want.