Pluto

"I'm sorry for your fate, child. I imagine you hate me."

- -Pluto to his daughter, Hazel, in The Son of Neptune

Pluto is the Roman form of Hades. As Pluto, he becomes more disciplined, militaristic, and warlike. While the Greeks feared him as the Lord of the Underworld, the Romans respected him as the god of wealth.

History
Pluto's regions are supposed to lie underground; and as he was the first who taught men to bury their dead, it was hence inferred that he was king of the infernal regions, whence sprung a belief, that as all souls descended to him, so when they were in his possession, he bound them with inevitable chains, and delivered them to be tried by judges, after which he dispensed rewards and punishments according to their worthiness. Pluto was therefore called the infernal Jupiter, and oblations were made to him by the living, for the souls of their friends departed.

Pluto was extremely revered both by the Greeks and Romans. He had a magnificent temple at Pylos. Near the river Corellus, in Bœotia, he had also an altar, for some mystical reason, in common with Pallas. His chief festival was in February, and called Charistia, because their oblations were made for the dead. Black bulls were the victims offered up, and the ceremonies were performed in the night, it not being lawful to sacrifice to him in the day time, on account of his aversion to the light. The cypress tree was sacred to Pluto, boughs of which were carried at funerals.

The Son of Neptune
Pluto appears in a flashback during World War II in one of Hazel's blackouts. He appeared to visit his daughter for her birthday, giving her a set of colored pencils and a sketch pad. He also apologizes for her curse, which causes anyone that touches the stones she pulls from the ground to have bad luck, saying she must hate him for it.

While Hazel's mother originally blamed Pluto for Hazel's curse, it was actually her fault. Pluto had sworn on the River Styx to offer her anything, but in her greed she wished for all the riches of the Underworld. Pluto warned her to ask for anything else as the greediest wishes cause the most sorrow, but in the end he obeyed her wish, giving Hazel the ability to pull precious stones and metals from the ground.

When Thanatos is eventually freed, Hazel asks if her name is on the list of escaped souls. The god tells her it is not, explaining that Pluto may have thought her life wasn't finished or it was an oversight.

When Hazel returns to camp, she is asked if her father has contacted her. She replies in the negative, but it is better that Pluto did not go to see her because he would have to acknowledge that she was alive and would have to bring her back to the Underworld. In Pluto's own way, not contacting her is his gift to her.

The House of Hades
When looking down at the farmlands at the base of the Apennines Mountains, Hazel can't help but think of her father's realm below the earth. She also remembers that the first time she met Pluto, she didn't know who he was. She also thinks back on how Pluto never helped her, not during her first life, her time in the Underworld, or even after Nico di Angelo brought her back to life. Hazel wonders if Pluto is doing her a favor, as Thanatos told her that by ignoring her, Pluto can allow her to live. Despite contacting her dad being a bad thing, Hazel prays to him for help.

Personality
As Pluto, he becomes more disciplined, militaristic, and warlike than he is as Hades. However, just like Hades he seems to care deeply for his children and any woman he falls in love with, being very protective of them. When first visiting his daughter Hazel, he apologized for her curse and offered her a present. He then went upstairs and tried to convince his current lover to stay where he could protect her and their child. He also cares enough that he ignored his daughter's existence, allowing her to live because she was also one of the souls that escaped the Underworld.

Appearance
As Pluto, he dresses in a dark suit with a black and platinum striped tie and a tombstone gray shirt. If you look at his suit closely, you can see the souls trying to escape from their agony, much like Hades' robe. He still has the silver ring on his finger, which are as pale as the rest of his body. He is so pale that it is described as being almost blue, like cold milk. He looks very much like Adolf Hitler, but this could simply be what people see when they look at him (as when Percy saw Hades, he looked like every evil dictator in history). He also doesn't have a mustache and is clean shaven, with greasy black hair. His eyes are also very similar to his Greek form, being fiery, angry, and full of mad power.

Abilities
Pluto, being the god of the Underworld, wields dark and necromantic powers. He is one of the three strongest gods of Olympus and is rivaled only by Jupiter and Neptune.
 * He has the ultimate powers that a god can possess.
 * Necromancy: As the ruler of the Underworld and god of the dead, he has divine authority and absolute control over the deceased.
 * He can summon and control legions of the dead and zombie warriors.
 * He can unleash endless waves of the dead or dark souls to attack his enemies.
 * He can control to a large extent the dead and spirits native to the Underworld.
 * Umbrakinesis: As the god of the Underworld he has absolute control over darkness and shadows.
 * He can control darkness and shadows thus using them for concealment as well as attack.
 * He can travel through shadows (Shadow Travel).
 * He is a shape-shifter with the ability to transform himself into various fearsome demonic forms.
 * Wields a Stygian Iron sword, capable of absorbing the essence or life-force of monsters and mortals respectively.
 * He has the power to induce fear in people using his Helm of Darkness.
 * Ferrokinesis: As the god of wealth, he can manipulate and control the riches under the earth's surface.
 * Geokinesis: As the god of the Underworld he has absolute control over the earth and the walls of the Underworld, Erebus.
 * He can control the earth (though to a lesser degree than Gaea as she is the primordial goddess of earth and all earth is her domain).
 * He can curse people so there soul will never leave their body and there body will turn to dust so their soul will be lost.

Trivia

 * Pluto is the name of the dwarf planet, once officially the smallest and farthest planet categorized.
 * Pluto is often considered to be a more decent side of Hades. Whereas Hades was considered the abductor of Persephone, Pluto was considered the loving husband of Proserpina.
 * While Pluto may have a similar appearance to Hitler, it was mentioned that World War II was caused by children of the Big Three Greek gods. This may only be because people see Pluto as an evil dictator, much like how Percy first viewed Hades the first time he saw him.