Percy Jackson/Heroes of Olympus headcanons

𝒞𝒶𝒾𝓃 𝐼𝓃𝓈𝓉𝒾𝓃𝒸𝓉

Zeus and Poseidon both suffer from Cain instinct. Hades does not. That's why when Percy met Thalia and Jason, they were almost immediately ready to throw hands, but when he met Nico, Bianca and Hazel he wasn't. If you go by mythology, Hades CHOOSE the underworld because he didn't trust his brothers to guard the remains of their father or the entrance to Tartarus, but the real reasons was probably to get away from Poseidon and Zeus trying to beat the fuck out of each other all the time.

But later? Later Nico develops the Cain instinct all of his own, once he's over his crush on Percy. Immediately upon seeing Thalia/Jason/Percy he is like "guess it's time to end you."

Hazel is a (not) innocent baby in the eyes of her cousins and brother and therefore is exempt from this because none of them want to fight her.