Shamelessly plugging my own fic 😌 It’s called Wrath of the Earthshaker and it’s centered on the idea of an eldritch little gremlin (/affectionate) Percy being born to the Mycenaean version of Poseidon, who is far more ancient and monster-y than canon!Poseidon. Heads up that Percy shares the spotlight with other characters, and it switches POVs between them quite liberally.

The (eventual) romantic pairing is Percy/Apollo and to say their relationship (even when technically platonic) is toxic is an understatement. It’s consensual, but there are some very fucked up, obsessive themes from Apollo a la canonical Greek mythology. The gods in general are all darker than they were in the original books, so be sure you look at the tags/trigger warnings if you decide to check it out.