Hades

Hades is a villain from the Kingdom Hearts series, originally from the 1997 Disney animated feature "Hercules."

Kingdom Hearts
''Lord of the Underworld. He's using the Heartless to try and take over the world. To get Hercules and Sora out of the way, he sent Cloud to fight them in the Coliseum. He heated things up in "Hercules" (1997).''

Kingdom Hearts: Chain of Memories
Ruler of the Underworld. ''Hades can't stand Hercules. He tricked Cloud into challenging Hercules to the death, but we put an end to his plotting.''

Kingdom Hearts II
''Lord of the Underworld. The last time Sora and his friends tangled with Hades, he was using the Heartless to try to take over the world. Together with Hercules, the three friends put a stop to his plans. But Hades is as evil as ever, and won't rest until he sends Hercules to the Underworld- for eternity.''

In Kingdom Hearts
Hades was one of Maleficent's allies, and apparently the most powerful villain on her team aside from her. He utilized the Heartless by supplying them as monsters to the Olympus Coliseum, for heroes to battle as per usual. However, he also gained the assistance of Cloud Strife by making a deal: If Cloud kills Hercules, Hades will lead him to Sephiroth (who he apparently does know the location of, as Sephiroth is indeed at the coliseum). Hades additionally provided Sora with a pass to enter the coliseum games. However, when Sora appeared to be winning in the Coliseum, Hades instructed Cloud to kill Sora as well. When the plan failed (either with Cloud refusing to deal the final blow to Sora, or with Sora defeating Cloud; it depends on the result of the battle), Hades had Cerberus attack Cloud. However, Hercules rescued Cloud and Sora defeated Cerberus.

As Sora left the Coliseum, Maleficent warned Hades not to be overcome by the darkness. Although Hades sent Maleficent away, claiming he could handle it, he ironically was not overcome at all (while the rest of Maleficent's followers and Maleficent herself ended up being overcome, with the other exception of Captain Hook). Strangely, Maleficent overlooked the fact that Hades was the immortal god of the dark underworld. This lead to the inevitable irony of Hades outliving Maleficent as well as being currently the only villain in the whole series to show in all the games and survive and will probably continue to survive due to him being a god.

When Hades learned of Maleficent's demise, he put matters into his own hands. Hades, determined on personally defeating both Hercules and Sora, opened the Hades Cup in the Coliseum. The long, grueling tournament had a battle with him near the end. Unfortunately for Hades, Sora defeated him in the battle. After a few more battles in the cup, though, Hades decided on a way for revenge.

In events very much like those in Hercules, Hades unleashed the four Titans upon the world (although only two are seen, it can be guessed that the other two and possibly the Cyclops were as well). When Sora reached the final rank in the tournament, he had to combat the Rock Titan. Upon its defeat, Hades apparently went into hiding.

In Kingdom Hearts: Chain of Memories
In Kingdom Hearts: Chain of Memories, Hades makes an appearance as a figment of Sora's memories. He, like the original game, hired Cloud to defeat Hercules. Eventually his plan fell apart and is forced to fight Sora personally. Defeating him grants you his character card.

Card
see:Hades (Enemy Card)

In Kingdom Hearts II
Hades is once again an antagonist in Kingdom Hearts II (unlike the rest of the villains, he has an excuse to be able to come back since he's immortal, and wasn't destroyed in the first game anyway). Most of Hades's dealings take place in the Underworld in this game. This time, in an effort to destroy Hercules, he tries to strike a deal with the dead Auron (whom he calls "The Mother of All Bad Guys"), offering him his life back with a clean slate, on the condition that he "Fight Hercules. In the Coliseum. To the death!" Auron refuses, and when Hades reminds him that he is talking to the Lord of the Dead, he responds "No wonder no one wants to die." Hades becomes enraged, and almost strikes Auron down until Sora arrives, needing to speak to him. But it ended up with Sora and gang running for it as Hades is invincible within his domain.

Pete suggests waiting for the Heartless to take care of Sora and company, but Hades knows better and dispatches Cerberus to take care of them instead. After Sora escapes the beast by using his Keyblade to open up a massive locked door, Hades decides to use him to open up the Underdrome, a massive arena long since sealed by Zeus. To this end, he kidnaps Meg, and traps her in the Underdrome, meaning Sora must use the Keyblade to rescue her, unsealing the Underdome in the process.

To celebrate the Underdrome's re-opening, Hades decides to hold the Hades Cup, in the hopes of killing Hercules once again. Trapping Auron's soul in a statue, he ordered him to take care of Hercules and Sora once and for all. But inevitably, the scheme fails, and a furious Hades dumps Meg into the River Styx with Hercules diving after her. Confident they'll be dead within moments, Hades overpowered Sora and gang until Hercules emerged, his full power restored by willing to risk his life to save Meg. Hades was soon quickly defeated and, while attempting to avoid a hit from Sora, loses his footing and falls down into the River Styx. Despite this, Hades manages to escape, though he doesn't appear to cause Hercules and co. much trouble after that.

Kingdom Hearts: Birth By Sleep
Hades could more than likely appear in this game, as the Keyblade weilders travel to the Coliseum, and serve as a boss battle.

In Battle
Hades is one of the more powerful villains on Maleficents side, although he usually prefers to send others to do the dirty work for him. Hades wields the power of Fire so all of his attacks use this element. One of his main attacks is to form balls of Fire and hurl them at his opponent. He punches his foes, covering his fists in flames. In both games when Hades gets angry his skin becomes orange and he enters a berserker like state, making him stronger and even making him invulnerable in Kingdom Hearts II.

Kingdom Hearts

 * "That little punk is your next opponent, kay?. Don't blow it, just take 'em out."
 * "Hey, it's like that old goat says: Rule #11: It's all just a game. So let loose and have fun with it! I mean, a casualty or two along the way is no big deal, right?"
 * "Stiffer than the stiffs back home. Still, suckers like him are hard to come by."
 * "''That little squirt took down that Heartless! Who'd have thought it?
 * "He's strong, he's kind, he's always there for you, and he's handsome to boot. He's perfect...perfect...perfectly INFURIATING! He makes me crazy!"
 * "Who invited you to the party? Stay out of this. This is my show."
 * "Oh, and there's one more rule I forgot, accidents happen."
 * "Whoa... light'in up, I'm as cool as they come OK."

Kingdom Hearts II

 * "What is so funny, you imbeciles! How dare you get a happy ending!  How DARE you!"
 * "You are FIRED!"
 * "Did you forget who you're talking to? I am the Lord of the Dead!"
 * "Were do they dig these freaks up? Geez, Louise."
 * "Dead... Dead is good! And I know just the warrior."
 * "Let's cut to the chase. Here's the deal am going to offer you."
 * "That's right! See, that's the thing. In the Underworld heroes are zeroes... Comes with the territory."
 * "This is my Underworld, you idiot! I'll handle this myself!"
 * "Have I ever told you about the killer coliseum we have right here in the in the Underworld?"
 * "Well, maybe... But why get caught up in the details."
 * "Laugh, laugh, laugh all you want!"
 * "This time, you're gonna play by MY rules."

During Battle

 * "That's it!"
 * "Is that all ya got?"
 * "Feel the heat."
 * "Take that!"
 * "I'm on fire!"
 * "Want some more?"
 * "This... isn't... happening!!"