A few known features are that she is the diametric opposite of KOS-MOS, wearing a black suit with red and dark purple highlights to contrast KOS-MOS's white, blue and grey uniforms. She also has dark skin, aquamarine eyes and silver hair and seems to possess a sapient personality unlike KOS-MOS robotic personality. It is also stated that her power is 3 times that of KOS-MOS and she emits red energy instead of blue energy. She appears to have no auxialiary weapons and appears to rely primarily on her physical strength and energy generation. The T-elos project is being headed by a man named Rot Mantel, a mysterious Vector scientist.

The Testaments are Wilhelm's closest assistants and servants. Characterized by colored robes with matching masks, the true nature and power of the Testaments is unknown. It is hinted that they possess the power to manipulate space, and they seem to be able to appear and disappear at will. Also, each Testament (as well as Wilhelm himself) appears to have their own E.S., a special kind of spacecraft that contains a Vessel of Anima. However, this has not been confirmed, and the E.S. could merely be powerful A.M.W.S. mechs, or an entirely new breed of gears. As of the end of Xenosaga Episode II, four Testaments have been revealed: red, blue, black, and white.

In terms of allusions and references, the four Evangelists John, Mark, Matthew and Luke who wrote the Gospels which are part of the Testament are sometimes depicted as wearing cloaks of these four colors.

Wilhelm hints that the role of the Testaments involves 'Influencing Space-Time Anamolies' that much becomes obvious when they resurrect Albedo and help to create a Space-Time Anamoly which engulfs the Omega System. This may be part of a much larger plan that is generally believed to involve recovering or returning to Lost Jerusalem.

The Testaments are incredibly powerful and may easily rank as the most powerful entities in the series. None of them appear corporeal and are more spirit, notably they apparently can also transform into larger Gnosis monsters which may explain their ability to teleport (chaos states at the beginning of Episode II that no human can teleport or enter hyperspace safely without significant protection.). They can also seemingly subvert the laws of physics to perform phenomal feats as Virgil states: "The laws which govern us are just too different" after he easily brushes aside the party.

• Black Testament: The first and oldest of the four current Testaments. He appears for the first time in Xenosaga: Pied Piper as a U.M.N. cyberterrorist named Elrich Webber who also went by the hacker alias Voyager. He was responsible for the death of Jan Sauer's (a.k.a. Ziggurat 8) wife and stepson. Of all four Testaments, we see him in action the most, though he doesn't appear much until the second game. In neither game has he spoken a word. He has very pale skin, no hair, and bright red eyes.

• Red Testament: The next oldest Testament (presumably). His identity rivals that of Kevin Winnicot, Shion Uzuki's lover who was killed by the prototype KOS-MOS. The primary justification for this theory is that Kevin and the Red Testament share the same voice actor, and indeed Shion recognizes his voice at the end of Xenosaga Episode II. Promotional images for Episode III also show a shocked Shion confronting the Red Testament. Also, at times a glimpse of Kevin's distinctive long black hair is visible beneath his hood. The Red Testament's true identity will be revealed in Episode III when the he finally unmasks himself. The Red Testament appears to be Wilhelm's right hand man and is described in some leaked production to be the leader of the Wilhelm's "Vanguard Forces" the Testaments. The two of them have extended intimate conversations in several scenes throughout both games; in one scene they even play chess together. In some of the trailers he is shown demasking himself; however, some white hair is seen, which suggests that it is an entirely different character altogether. Some have suggested that the character of Rot Mantel, the cheif Vector scientist working on the T-elos project, is actually the Red Testament operating in disguise. Interestingly, "Rot Mantel" is "Red Cloak" in German.

• Blue Testament: This Testament was created during the course of the Xenosaga Episode I. He is known to be Lt. Virgil, a man who was killed by KOS-MOS during the Gnosis attack on the Woglinde. He appeared to have a violent hatred for Realians, and suffered from the potent DME Addiction. Even as a Testament his face still shows the cracking pattern characteristic of people with this addiction. In a mysterious comment in Xenosaga: Episode I, he refers to chaos as boss. He first appears as the Blue Testament on the Song of Nephilim where he bails out Albedo who was just defeated by Shion, Jr. and their companions. Albedo departs, telling the Blue Testament to give 'him' (most likely Wilhelm) a message: "'it' (most likely either Proto Merkabah, MOMO, or U-DO) belongs to me (Albedo himself). When Albedo departs Virgil attacks the group using his new found powers as a Testament, which include but are not limited to; subverting the laws of physics and transforming into a Gnosis. Moreover, the type of Gnosis that the blue testament transformed into (Ein Rugel) was also the same type of Gnosis that the Black Testament Voyager turned into when Ziggy aka Jan Sauer confronted him over 100 years ago. Testament appears again after Albedo summons Proto Merkabah to Second Miltia and he is reprimanded by the Red Testament to just let Albedo be for the while. When the Red Testament shows him just what his and Wilhelm's plan is and how it relates to Albedo, he reluctantly backs off.

• White Testament: The newest Testament, who only appears at the very end of Xenosaga Episode II. His identity is also officially unknown. Some believe him to be the U.R.T.V. Albedo Piazzola, who had recently died in a confrontation with his brother Rubedo (a.k.a. Jr.). This theory is supported by the White Testament's and Albedo's similar voices, and Wilhelm's comment after introducing him: "I said it was a shame, didn't I?" In the first episode, he had mentioned that it was a shame to give Albedo such a small role. Nothing definite is known about this Testament as yet, aside from the fact that Wilhelm refers to him as the "weaver of the eternal circle of Zarathustra"—a fact that may indicate a large role in Episode III: Also sprach Zarathustra. There is also theory that Chaos (Xenosaga)|chaos is another probable option for the White Testament, however, during the ending credits chaos is seen sitting onboard the bridge of the Elsa directly parallel from Hammer's seat, just after Shion says her goodbyes to Jin and they are all waving to the ship, therefore unable to be with Wilhelm during the meeting. On another note, with Blue Testament/Virgil referring to him as "boss", it is almost certain that chaos would be a much higher rank than a Testament, which would also grant him communication with Wilhelm using the same telepathic means Virgil and Red Testament used in Xenosaga Episode I and would still give backing to his unexplainable powers. As a final detail, it is highly unlikely as he is the so-called Jesus of the series, hence his real name of Yeshua that is revealed in the ending of Episode II. 

The Black Testament, Voyager

The Red Testament

The Blue Testament, Virgil

The White Testament

Wilhelm is the mysterious founder and CEO of the largest interplanetary conglomerate, Vector Industries. He also served as the Executive Committee Director of the Galaxy Federation, up to a decade ago. To be the founder of Vector and the Executive Committee, Director Wilhelm must be very old, much older than any normal human could possibly live. He is seen still in his youth during the events of Pied Piper and leaked production notes suggest (this may have canonically changed) that he has existed since the discovery of the Original Zohar 4000 years before the present game time. Some writings suggest that he may have even funded the Mitsuda expedition (featured at the very beginning of Episode I) that uncovered the Zohar in the first place. It is speculated that Wilhelm might not be entirely human. Wilhelm is one of the most suspicious characters in the Xenosaga series; it seems he is manipulating every other conglomerate and individual for his own personal gain. Wilhelm also has an affinity for referring to life's situations as if they were all a part of some universal theatrical play. Wilhelm is also an avid fan of chess, adding fuel to the dramatic approach of his manipulations.

As the head of Vector, Wilhelm has control of the UMN transport gates, meaning absolute control of galactic transportation, communication, and, most importantly the realians. As Virgil points out in Episode I, a control code is built into all realians, which Wilhelm would obviously know and be able to take advantage of. Although it appears that U-DO was the force behind the Realian riots during the Miltian Conflict, an argument could be made that someone such as Wilhelm could have been manipulating events behind the scenes as a distraction. Regardless of which case is true, Wilhelm could at any time take control of every realian in the galaxy and create a massive army.

Wilhelm uses an artifact called the Compass of Order when he makes a move. He is often seen staring into it, sometimes obsessively. It is quite possible that Wilhelm is using the Compass of Order as a vision into the future. With such knowledge, Wilhelm could easily manipulate circumstances in the present to aid him in the future.

Wilhelm's assistants are the Testaments, powerful and mysterious agents. The extent and nature of the Testaments' power is unknown, but they seem to be Wilhelm's closest personal advisors and subordinates. By the end of the second game we have seen four Testaments, each dressed in different-colored robes: black, red, blue, and white. All of the Testaments have previously been killed in some way or another, and they were somehow resurrected by the intervention of Wilhelm and became Testaments.

At the end of Xenosaga Episode II, there is a brief scene involving chaos and Wilhelm. Chaos explains that he will not hold back, and Wilhelm seems delighted that chaos is finally "entering the stage." Wilhelm then addresses chaos as "Yeshua," which may hint to a past partnership or rivalry between the two men.

Wilhelm also appears to own an E.S. or E.S.-like silver mech which is briefly glimpsed in the epilogue at the end of Episode II. The mech appears to have a long spike protruding out from the elbow joint of its left arm and a series of tubes or wires stretching out from the elbow joint of its right arm, curving around its back and connecting with the mech's right shoulder. A strange glowing blue symbol or object can also be glimpsed somewhere on the mech's chasis as well though it was obscured by the mech's own shadow. This unit will more than likely make a return appearance in Xenosaga Episode III: Also Sprach Zarathustra.

Wilhelm's link to the collective mythos upon which Xenosaga is based may lie in the subtitles of the Xenosaga games, Der Wille zur Macht, Jenseits von Gut und Böse and Also Sprach Zarathustra. These titles are shared with publications by Friedrich Wilhelm Nietzsche, whose middle name is shared by Wilhelm himself. This link helps to attribute Wilhelm to his role as an enigmatic manipulator of the events which unfold in Xenosaga.

The name Wilhelm is also a contraction of the German for Will and Helmet, or, as another source suggests, "the will to protect". This would imply that Wilhelm’s intentions are good, although that is definitely unclear at this point.

Some have noted that physically and personality wise Wilhelm is the direct opposite of chaos. He has pale skin and red eyes to chaos's brown skin and blue eyes. Wilhelm is also an active manipulator of nearly all significant events while chaos takes a laid back pacificistic role to all things.

Canaan is a special Realian created by Vector Industries. He is the only Realian (except for MOMO) who can pilot an E.S., specifically E.S. Asher. He is not designed like the other Realians and is referred to as an "Enhanced Memory Model" model by MOMO when they first meet in Helmer's office.

Canaan was sent on a mission during the Miltian Conflict by Lieutenant General Helmer along with chaos to retrieve the U.R.T.V.s and the Y-Data. During their mission the U-TIC Organization activates the Song of Nephilim. Canaan starts to become affected by it, but he fights off being overcome by it. Nearby Federation Soldiers in A.M.W.S. are affected, and start attacking Canaan and chaos. Jin Uzuki arrives in time and aids them. Shortly after that Jin shows them to the U.R.T.V.s. location at Labyrinthos, headquarters of U-TIC. Margulis appears, and he and Jin fight. After the fight Jin entrusts Canaan with information regarding the Miltian Conflict, which is also a fragment of the Y-Data. After Jin leaves something happens to Canaan (unknown if it affects chaos at all) and the information is inaccessible to him. After that is a mystery but after sometime passes they find two of the U.R.T.V.s. They are Rubedo aka Jr. who is carrying out a wounded Nigredo (aka Gaignun Kukai). They rescue them both but no other U.R.T.V.s. are reported being saved. It is unknown if Albedo is rescued by them or not. No mention of them finding him is made so far.

14 years later Canaan is still unable to read the data that is locked inside his head. He has spent some time at Vector's 2nd Division on Second Milita trying to retrieve the data. Representative Helmer asked him to aid Jr., chaos, Ziggy, and MOMO as they are under attack by U-TIC A.W.M.S. Units. He arrives in time and finishes the fight, by attacking Pellegri. During the fight their E.S. units freeze as if they're stopped in time. This is possibly their Vessels of Anima reacting to each other, or some unknown phenomena causing this. (the player can see someone for a brief second in a E.S. with arms crossed on a building. It is not known who is standing there.) Eventully during the game he joins the main characters (as an NPC) as they return to Old Milita to extract the data and anaylze it.

 Gaignun Kukai is the chairman of the Kukai Foundation, a special organization based in Miltia, Gaignun bears a sharp resemblance to Jr. in spite of the fact that Jr. is legally his adopted son. He is the perfect leader for the massive and wealthy Kukai Foundation. Gaignun has black hair and deep green eyes. He has a gentle personality and is well respected both within and outside the Foundation. Gaignun is listed as the first son and heir to the industrialist Soze Kukai.

Gaignun Kukai is reallyU.R.T.V. Unit #669, who is a biological weapon designed to combat U-DO. U.R.T.V. Unit #669 is nicknamed Nigredo, a reference to his black hair. Gaignun can telepathically communicate with Jr. and Albedo and can use his voice to hypnotically manipulate people, if need be he can telekinetically destroy a person. "Kukai" was a fictional persona created by the Second Miltian government as a means to pool their special operation funds. Following the Miltian Conflict and Helmer's rescue of Gaignun and Jr., they took on the Kukai surname to justify and establish the Kukai Foundation. This also allowed the U.R.T.V. units to live their lives more normally.

In Episode II, Gaignun's past relationships with Albedo and Jr. are explored. which include subconcious dives into Sakura Mizarhi's mind in order to allow her to speak once again. These adventures showed the rift growing between the trio of U.R.T.V. units, which eventually led to a breakdown during the Miltian Conflict, causing Albedo to come into contact with U-DO and become insane. At the end of Episode II, Gaignun apprarently suffers from a double personality; one part is Gaignun, the other is Dmitri Yuriev. Dmitri most likely created Gaignun just as a host for his body, for Dmitri has transmigrated from body to body for over 100 years