Reading fantasy book with Christian mythology

Is reading fantasy book with Christian mythology sin? Or mortal sin? Or is it ok. For example I borrowed in library the book Good Omens by Pratchett & Gaiman. It is about Armagedon inspired by Bible. It’s written by funny style. Can it be considered blaphemous. I’d like to read it, but I don’t be in sin with it.

I have read also Sandman by Gaiman. There is also comic book series called Lucifer based on Sandman. Here is anotation of the first book from series:

Lucifer Morningstar, the former Lord of Hell, is unexpectedly called back into action when he receives a mission from Heaven. Given free reign to use any means necessary, Lucifer is promised a prize of his own choosing if he fulfills this holy request. But once he completes his mission, the Prince of Darkness’ demand shakes the foundation of Heaven and Hell. Now as his enemies unite to stop his reemergence, Lucifer gathers his forces as he prepares to launch his new revolution.

Can I read it? What is allowed for Catholic?

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