Can't Unhear It: You will be reading every line that comes out of Hades' mouth in James Woods' voice. That is a fact. To a lesser degree, don't be surprised if you find yourself hearing Lisa Kudrow while reading Aphrodite's lines.
Character Rerailment: The whole point of this fic is to take the Hades from Disney's Hercules movie and develop him into something closer to his original mythological self. Aside from redeeming him and adding his relationship with Persephone, this also includes actually having him use his iconic invisibility helmet from classic Greek Mythology.
Jerkass Woobie: Hades' whole backstory. Sees his fatherviolently rape his own mother, then swallows both him and his brother Poseidon where they had lived in his stomach for years. After they get out of Kronos' stomach, his youngest brother Zeus decides that he's the leader since he saved them and grows up to become King of Olympus and gets all the love and glory, while Hades is ostracizedby his fellow gods and is considered by them to be the resident Butt Monkey (the opening scene in the movie is a good example of why he perceives himself as an outsider - even Poseidon doesn't hold him in high regard). Not only this, when he was younger and exploring the Underworld, he came across Kokytus, a waterfall in his domain. Being curious and being King, he tasted the water as he missed Olympus, but loses his Power Glow - thus explaining why he does not glow unlike the other gods. On top of that, the only love he had known died tragically, forcing him to contemplate suicide. This long Trauma Conga Line ultimately drove him to evil.
Nightmare Fuel: Most of Hades' childhood. Even if one excuses being eaten alive AT AGE FIVE, there's also that Hades knows for a fact that his father RAPED his mother frequently.