Shakhan. Ruler of Aveh; he assumed power in a military coup backed by Solaris. Although Shakhan is little more than a puppet for Solaris, Bart has vowed vengeance on him for killing his family and assuming the throne.
Gear: Name unknown

   Kelvena. Leader of the Elements (though Dominia seems to call all the shots), a special Solaris force resembling the Turks or Leader's Force. Kelvena represents the element of Water.
Gear: Marinebasher

   Dominia. Earth member of Elements and the de facto leader. She comes from the country of Elru on the surface, and was the sole survior of Grahf and Id's attack. She now harbors a strong condescension towards the "Lambs", believing that only the strong can survive.
Gears: Bladegash, G Elements

   Tolone. The Wind member of Elements, a cyborg that possesses a gin 'n tonic futon positronic photon brain, making her extremely smart. That's about all there is to say about her.
Gear: Skyghene

   Seraphita. Newest member of the Elements; she replaced Elly's position as the Fire Element after Elly left. She acts like a little kid, because, well, she IS a little kid. May exceed even Chu-Chu in annoyance factor.
Gear: Grandgrowl

   Grahf. Actually Lacan, Fei's 4th incarnation. He went postal after Sophia was killed at Nisan and was split into two -- his spirit was passed on to his next incaranation (Fei), while his body became Grahf and went on a quest to find the power to destroy the universe in revenge. Since his body couldn't live forever, Grahf started possessing other bodies, and is currently in the body of Wong Khan, Fei's father. He allies with Krelian, though he is more interesting in acquiring the "power" to destroy the world than in reviving Deus. Ends up sacrificing himself to protect Fei from Deus.
Gears: Alpha Weltall, True Weltall

   Deus. The big head honcho behind it all, Deus is actually a biological weapon from another planet (and one that resembles a giant turtle, no less). It was deemed too powerful by its creators, so they tried to dispose of it by shipping it off in the Eldridge. However, Deus (being an intelligent entity) found out about this and destroyed the Eldridge, causing it to crash onto the planet where Xenogears takes place. It must absorb the populace of the planet in order to regain its powers.

   Id. Id is actually one of Fei's alternate personalities, representing his id (duh). He took over Fei's personality after Fei 'awakened' for the first time in Lahan, and served as Grahf's right-hand man for many times, during which time he destroyed Dominia's homeland Elru and fought Ramsus, before being sealed up by Fei's father Khan. Id is really the victim of the Coward, who blames all his problems on Id and incites him to violence against the world.
Gear: Weltall - Id version

   The Coward. Fei's third personality, the Coward is Fei's superego and the one that messed up his mind so badly. After Khan sealed up Id, his superego created his "normal" self (the ego) to deal with all his problems while the Coward remained in denial, reliving his memories of his childhood. Eventually, Fei and Id team up and force him to merge with them to form the "normal" Fei.

   Kahran Ramsus. Commander of Gebler and the real ruler of Aveh; he at first is brash and confident, until he learns that he was actually a manufactured Contact that he was considered useless after Fei was discovered. He then goes postal and insists on killing Fei with his own hands. He is finally persuaded to turn good, and then mysteriously vanishes from the game.
Gears: Vendetta, Wyvern, Amphysvena

   Miang. With Cain and the Gazel, one of the first humans created by Deus, and the mother of all of humanity. The original Miang died long ago, but any woman can become the new Miang via the Ouroborous, I mean, Urobulos Gene. The current Miang is a former member of Elements that now spends most of her time hanging out with Ramsus for unknown reasons.
Gears: Miang's Gear, Opiomorph

   Emperor Cain. 10,000-year old Emperor of Solaris; he was one of the first humans created by Deus. He was survived so long because the only person that could kill him was himself... so Krelian created a clone of Cain, Ramsus, to do just that.

   The Gazel. The real rulers of Solaris, at least until Krelian arrives, the Gazel Ministry was created by Deus alongside Cain and Miang. Its members lost their lives in the Diabolos incident, and their personalities were stored in the SOL-9000 supercomputer. They frequently argue with Cain and Krelian, both of whom are attempting to manipulate them onto their side. Krelian finally gets the upper hand when he erases them from the SOL-9000's data banks.

   Calamity. The prototype for the Siebzehn and Achtzehn (I guess this would be the Sechzehn). It malfunctioned and somehow ended up under the Aveh desert. Don't ask me.

   Vanderkaum. A weird-looking guy with a metal place (?) in his face. He was the former commander of the Gebler forces in Aveh before Ramsus showed up, at which point he was promptly demoted to border patrol in the Kefeinzel. He is obsessed with the Kefeinzel's gigantic main gun and insists that it is the best weapon in any situation, despite modern Gear tactics. Needless to say, the Kefeinzel does not last long under his command, and is soon destroyed by Fei and Maitreya. He escapes in his Gear, the Dora, but his once again defeated. Grahf then shows up and grants him "the power", causing Fei to turn into Id and destroy Vanderkaum and the Dora.
Gear: Dora

   Redrum. Not exactly a character, but worth mentioning because he's such a pest. Redrum is a Wels that somehow ended up inhabitating the Kislev sewers. Its last remnant of its humanity is a bell amulet that it keeps. Apparently harmless, Redrum gets blamed for the murders in Nortune and is killed by Fei's party, though it was actually Fei (as Id) who killed Rico's gang. One of the kids in Billy's orphange is the son of the person who was turned into Redrum.

   Elly's Squadron. Elly's Gebler squadron consists of five members: Renk, Vance, Broyer, Stratski, and Helmholz. None of them really have any individual personality, but they are all insubordinant to Elly and don't understand her desire to help the Lambs. They vanish after the Hecht incident, but later turn up on Disc 2, now on your side.
Gears: Swordknight, Wandknight, Clawknight, Aegisknight, Schpariel

   Krelian. The chief villain of Xenogears, even though he doesn't show up until halfway through. An ally of Roni's in the war 500 years ago, he went postal after Sophia died and now seeks to return the universe to its origins in the wave dimension. He is secretly pulling all the strings in Solaris.

   Bishop Stone. Jessie's archenemy, Bishop Stone works for Solaris to police the -Ethos- and eliminate those who stray too far from Solaris's rule. His real name is Stein, though it's never exactly clear why he goes by "Stone" instead.
Gear: Alkanshel

   Wong Karen. Fei's mother. Karen herself was not evil, but soon after Fei was born, Miang found out that Fei was the Contact and took over Karen's body. Miang/Karen then subjected Fei to a series of tests to judge his psychic capabilities, in which he killed a lot of Solaris researchers. Meanwhile, her husband Khan remained ignorant of Karen's change, until Grahf showed up and made Fei use his energy to kill Karen. Shortly before her death, Karen returned to normal (not Miang) and shielded Fei from the blast at the cost of her own life.