Percy/Oceanus?
Okay so like, two main ways I'd write this
1. Percy is all grown up and shit and like, Okeanus is sulking from semi-losing the war (he retreated so kinda lost?) And is hanging out in Alaska.
Percy goes there for a break from Godly stuff and runs into Okeanus and just... Things go from there.
There's at least one major fishing trip and two instances of people mistaking them as a couple before they actually get together.
2. Percy is captured in book 5 after the Princess Andromeda by Okeanus' forces instead of being found by his dad.
Honestly several ways this can go but since I view him as pretty chill overall he's basically just keeping Percy out of the war. And obviously titans win cause prophecy kid aint there and Poseidon doesn't go up to help without Percy's nudging so-
And Kronos is like "uh, prophecy kid, i kinda gotta kill him?" And Okeanus is like "finders keepers fuck off he's mine now" and Kronos is like "fine whatever, keep him out of trouble" and anyways Percy basically slowly gets close to Okeanus after several years of anger and pain and stuff cause he never really finds out what happens to his friends.
Send me characters and I’ll tell you how I’d write their relationship