Hex (Classic)

Hex (voiced by Khary Payton), also known as Hexlord, is a self-proclaimed "Master Magician" who desires to rule the world with his unmatched powers. He possesses five "magical" charms called the Charms of Bezel that give him the powers of levitation, fire, reincarnation, lightning, and luck, in addition to his own spellcasting abilities. It is unknown how he possesses powers even without the charms (revealed in an Enhanced Version of the episode to be highly advanced Bezellian technology), but since it's implied in In Charm's Way that Charmcaster was trained in manipulating mana, it was probably the same for him.

Though like all the villains of the show, he's fought Ben several times, but he's more Gwen's enemy than Ben's, as he attacks her in all his appearances except Don't Drink the Water, and show more hate and rancor toward her (when he escapes from prison in Tough Luck, he clearly states he wants to get revenge on Gwen, not Ben). This technically make him Gwen's Vilgax, though he appears less often than the galactic conqueror.

Original series
In Lucky Girl, he attempts to steal an ancient spell book known as the "Archamada Book of Spells", dating back to the 16th century and containing powerful spells that, combined with the Charms, give the wielder unimaginable powers (revealed in an Enhanced Version that the combined powers of the Charms allow him to make the spells real). However, the Charm of Luck falls into Gwen's possession during Hex's fight with Ben, and she soon learns to utilize its power (the first hinting of Gwen's latent powers). Despite Hex's attempts to reclaim the Charm and the Book, he is eventually defeated by the Tennysons and arrested, while Gwen destroys the Charms.

Hex returns in Tough Luck, his niece Charmcaster breaks him out of prison. Together, they search for the Keystone of Bezel, which he plans to use to recreate the other five Charms and multiply his power tenfold. Again, Gwen gets ahold of the Keystone and is soon attacked by the pair. Hex fails again due to both the Tennysons interference and Charmcaster betraying him so she can take the Charms for herself (though she fails as well).

Hex (who is revealed to have been possessed by Ghostfreak once defeated) appears in Ben 10: Protector of Earth, as a boss that Ben faces at the end of Effigy Mounds. Hex then reappears in Don't Drink the Water, having aged into an old man since his last appearance. Learning of the Fountain of Youth, he tracks it down and uses it to become immortal. However, Ben, reduced to a toddler by the effects of the Fountain, uses Heatblast to try and evaporate the Fountain due to being taunted by Gwen so much he has a tantrum and goes supernova hot, allowing him to evaporate the water, which overexposes Hex and reduces him to an infant. Hex is last seen in Charmcaster's hands, where his niece enjoys taunting him at his expense. Hex was mentioned in the Vilgax Attacks video game, by Charmcaster when she's confronted by Ben on Terradino, stating that Ben has got a lot of nerve facing her after what he did to her uncle, presumably referring to the Fountain of Eternal Youth.

Alien Force
He eventually come back in the third season, where it's revealed he has seemingly made up with his niece between the two series, and now lives in a tall, Japanese-style mansion where he keeps all his books of magic. He turned back to his original age, and his look is mostly the same than before, though his clothes are now fully red instead of black and red, and his face is whiter than before, making it look even more like a skull. Khary Payton reprises his voice.

In Time Heals, Gwen infiltrates his house to steal the Grimoire of Archamada, and, despite Paradox's warning, use it to time travel to the past, stop Ben and Kevin from hacking the Omnitrix and preventing Kevin's mutation. Though she succeeds, her action causes Hex to take over the world. No thanks to his magic, the Master magician knows that Gwen is responsible for the creation of this future, and tries to prevent her from turning back the future to normal. However, after a short fight against Charmcaster and a possessed Kevin, Gwen finds the prison and frees Ben, who helps her getting back the Grimoire of Archamada and gaining enough time to go back in the past and prevent herself from changing the future.

Powers and abilities
Hex is a master magician this is proven by his abilities to use his staff (a staf that only a master magician can use) and the ability to activate the charms of bezel. With the charms of bezel he is capable of levitation, reincarnation, manipulation of fire, ligthning and probability without using his spells.

In alienforce in his own appearance he has showed that his abilities has grown, by knowing that gwen created a timefold and by ruling the world without the charms of bezel.

Trivia

 * It is revealed by Dwayne McDuffie that Hex is Charmcaster's father's brother and he raised her.
 * Like most powerful humans in the series, his abilities are probably related to alien genetics or technology. This would seem particularly true because Charmcaster, his niece showed a connection to absorbing mana, the life enery related to anodites, the alien source of Gwen's magic.
 * Although Hex is a master magician, he is not nearly as strong as Gwen, as he can’t use the Book of Archamada without the charms of Bezel, while she can.