I have a thing for mythos too.
(And Methos, if you're a Highlander fan)
How much do I intentionally use mythology in my stories? They're the deliberate foundations of my urban fantasies. How far do I twist them?
Fafafafafaaaaar.

Oh, then there are the symbols that cross multiple myths from around the world. Circle of Life anyone? (Go ahead, sing the song form the Lion King, I'll wait.) What about my personal fave, the dragon? Eh? Eh? I'm on team "Benevolent until You Piss Them Off" for the record.
How can any author resist those writing prompts?
Now, the funny part. I don't intentionally use established mythology in my epic fantasies. However. By the time I'm reading the almost-nearly-final draft, I see pieces of assorted familiar myths waving from the pages. Jeffe pretty much nailed the reason for that on Sunday -- "[myths] are iconic embodiments of our understanding of the world - both natural and supernatural." Without those bits of common understanding, I don't know that the story would resonate with readers.
Dear, dear readers, if you could create a story for a secondary or tertiary character from an established myth whose story would you write?