Aggregor

Aggregor is an Osmosian warlord with lethal absorbing powers. He was introduced in Fame and served as the main antagonist of season one of Ultimate Alien. His main objective is to get to the Forge of Creation and absorb the powers of the Celestialsapien, which he refers to as the "Ultimate Prize," so he can become omnipotent. To achieve this goal, he absorbed the abilities of various powerful aliens he captured from the Andromeda Galaxy in order to become strong enough to search for the four fragments of the Map of Infinity, the one item which will lead him there.

Appearance
Aggregor's appearance is, for the most part, similar to that of a human. However, he has small flesh-colored horns coming out of his head and red eyes ringed with black circles (a sign that an Osmosian has recently absorbed raw energy). He has long black hair and has pale skin. He wears a brown tunic and wields a spear-like weapon that he can use to fire blasts of red energy (presumably plasma or electricity). In the episode Escape From Aggregor, his species confirmed to be Osmosian.

After the absorption of the Andromeda aliens, Aggregor went through a mutation similar to Kevin's, becoming a powerful amalgam of the five aliens. Unlike Kevin's mutations however, Aggregor's new form was more refined and balanced in appearance, rather than a random mixture of parts, and not lacking the full potency of the five aliens powers, a result of a special machine he used. In this form, he has his hair and horns (Ra'ad's coloring) from his normal form, Bivalvan's legs and hands, Galapagus's torso, Andreas' arms, P'andor's faceplate on his neck, and a Ra'ad-based head. His eyes have turned blood red and he is also much taller than before, standing at approximately 10' (though it is still shorter than Humungousaur in his normal form).

Powers and Abilities
Being an Osmosian, Aggregor has the ability to absorb matter and energy from anything in order to use it in various way. While Kevin currently relies more on his matter-absorbing powers, (due to his lack of control of his powers when absorbing energy), Aggregor appears to have fully mastered his powers (though Dwayne McDuffie confirmed that he still lacks experience with absorbing pure energy), and prefers absorbing the energy and DNA of other life-forms, acquiring 1/10 of the original creature's power without mechanical aid (this is the biological limit for Osmosians).

Unlike Kevin, (at least until he used a machine, which may be of similar technology used by Vilgax, to enhance his absorbing powers) the powers and abilities he absorbs don't drastically change his appearance (due to his advanced age as Kevin 11,000 was able to do the same in Ken 10): for example, when he absorbed powers from one of Galapagus' friends, his appearance stayed the same, though he could now grow six hollow ports on his torso to create wind attacks or fly at will.

Also, while Kevin, when he absorbed powers from the Omnitrix aliens, left them unharmed (as he absorbed the transformative energy of the Omnitrix rather than the energy and DNA of the aliens' themselves), Aggregor absorbs all of the energy from living beings, including their life force, leaving behind nothing but a shrunken husk (except when he used his machine to surpass his absorption limitations which allowed him to even absorb the aliens' bodies by turning them into pure energy). This allows him to retain their powers for extended periods of time and gives him better control over their powers as well as a less drastic mutation. Just like Kevin, he needs physical contact with a creature or object to absorb its energy and matter.

In addition to his matter and energy-absorbing powers, Aggregor is a highly skilled hand-to-hand combatant and relies on a spear-like weapon which he can use to stab his opponents, fire blasts of red energy (presumably plasma or electricity), or conduct energy to substitute his own ability to absorb energy due to his lack of experience with absorbing pure energy. (Dwayne McDuffie confirmed that when Kevin attacked and subsequently defeated Aggregor at the end of The Forge of Creation, he tried to absorb Kevin's attacks but could not due to his lack of experience with absorbing pure energy.) As seen in "Andreas' Fault", he can use his spear-like weapon to summon his ship as well as lift and levitate objects and people with an electromagnetic aura (similar to Brainstorm's abilities) that is the same whitish red energy from his spear. In "Fused", Aggregor explains that his weapon is designed to combat creatures that can control and manipulate energy (particularly electricity), as seen when he used it to redirect Gwen's mana blasts and electrocuted Brainstorm (nearly killing him in the process).

Much like Ben's archenemy Vilgax, he uses robot drones as his army rather than living soldiers, though his robots are more humanoid in shape and stature than Vilgax's. However, he largely prefers to carry out his plans himself rather than let his minions do the work for him, unlike Vilgax and the Highbreed. He has captured and later re-captured the five Andromeda aliens by himself, and didn't even mind to once disguise himself as a Plumber to do it.

After his mutation in Ultimate Aggregor, Aggregor absorbed the five aliens from Andromeda, resulting in him having their combined powers. These new abilities included superhuman strength and durability (he was capable of shrugging off a massive beating from an enraged Humungousaur (who subsequently dropped a building on him) with no apparent injury or discomfort), immunity to mana-based attacks, radioactive energy beams, heat generation, electric blasts, water and wind generation/manipulation, seismic/shock wave generation (he was capable of destroying a fair portion of Los Soledad by slamming his fist into the ground), incredible swimming, digging, and flying abilities, energy shields, telepathy, intangibility, and the ability to survive in virtually any environment. Aggregor's new powers also allowed him to travel through space unassisted, meaning he didn't require his ship anymore.

Weaknesses
Before he absorbed the Andromeda Aliens, he seemed very dependant on his spear as shown in the first five episodes he appeared in (particularly Fused). Even after absorbing the Andromeda aliens, he was harmed by Max's plasma gun and Ultimate Cannonbolt's attacks and It should be noted that the only reason Ultimate Cannonbolt lost was because he was caught off guard and not in his ball form. As seen in The Forge of Creation, Ultimate Kevin revealed that Aggregor could be harmed by Jetray's neuroshock blasts as well as Swampfire's fire blasts and Brainstorm's electric blasts. Without his spear, Aggregor is vulnerable to energy-based attacks unless he were to use his powers to absorb them. However, because he lacks experience with absorbing pure energy, doing so could be potentially dangerous to his physical and mental state (though he would likely be unaffected by the later, as he is already apathetic and unstable to begin with). Dwayne McDuffie even confirmed that Ben could've beat Aggregor in Fused had he not used an electrokinetic alien and if he had not underestimated him.

Ben 10: Ultimate Alien
In the series premiere, Fame, after Bivalvan was defeated by Ultimate Spidermonkey, he explains that Aggregor captured him along with four others but they managed to escape to Earth. At the end of the episode, instead of the Plumbers who Bivalvan was expecting to send him back to his home planet, Aggregor appeared, having found him somehow. His first line was "No one escapes me, Bivalvan". Bivalvan is then heard screaming offscreen as Aggregor tortures him before taking him away.

He appeared again in Escape From Aggregor, where Galapagus told the tale of how he and the other four aliens were captured and escaped. Aggregor revealed that his plan was to absorb the full powers and abilities of the five aliens he captured using a machine he had built back on his home planet and make himself invincible so he can obtain the "ultimate prize". At the end of the episode when Ben and the others sent Galapagus back to his home world, the Plumber agent that was transporting him is revealed to be actually Aggregor in disguise.

He appeared again at the end of Too Hot To Handle after Ben, Gwen, and Kevin succeeded in subduing P'andor and had him taken off the planet. The Osmosian attacked the ship transporting him before abducting it. Aggregor's attack had caused the glass to be smashed open, resulting in the pilots being flung into space while he recaptured P'andor.

He then appeared at the end of Andreas’ Fault, where he found Andreas buried underneath the remains of a Forever Knights' castle before transporting him back to his ship and putting him in a stasis pod alongside Bivalvan, Galapagus, and P'andor with only Ra'ad remaining to be recaptured, after which he states that then "the fun begins".

Ben, Gwen and Kevin finally met him face to face in Fused, where it was revealed by Ra'ad that Aggregor was using the signal of the Ultimatrix to locate the aliens. The Amperi then attempted to destroy the Ultimatrix to prevent Aggregor from finding him, but the Ultimatrix had attempted to scan his DNA at the same time, resulting in Ra'ad being trapped in the Ultimatrix and his form being the only one Ben could turn into. When Aggregor arrived and easily defeat Kevin, Ben transformed into Ra'ad's form (which he named AmpFibian). Aggregor attempted to use Ben/AmpFibian as a replacement for Ra'ad, but Gwen used a teleportation spell to transport the trio to Kevin's warehouse. Aggregor returned to his ship to have his sensors track the Ultimatrix signal, but it was offline because of Ra'ad's disabling of it. Gwen and Kevin rebooted the Ultimatrix to separate Ben and Ra'ad, allowing Aggregor to find them again. Knowing he would be coming, Ra'ad quickly fled just as Aggregor came in through the roof again. After dispatching Kevin and Gwen, Ben faced off against him as Brainstorm. Unfortunately, Aggregor's spear weapon neutralized Brainstorm's yellow lightning attacks and easily defeated him. Aggregor then attempted to use the Ultimatrix to forcibly (and extremely painfully) change Ben back into Ampfibian for his plan, almost killing him in the process, but Ra'ad (having been given a lecture by Kevin) returned to save Ben. In the clash between Ra'ad's whitish blue lightning attacks and the whitish red energy blast of Aggregor's weapon, the warehouse exploded, but Ben and Gwen were able to escape while Aggregor transported Ra'ad back to his ship during the blast. With all five of his prisoners recaptured, Kevin feels that Aggregor has won, but Ben, having scanned all five aliens, vows to use their powers and abilities to stop Aggregor and save them.

In Ultimate Aggregor, it was shown that after Aggregor escaped the warehouse's explosion with Ra'ad, he traveled out into the desert to call his ship and transport him. However, he found himself ambushed by Plumber agents out to get him for his murder of their noble comrades and his kidnapping of aliens. Unfortunately, Aggregor was prepared and unleashed a torrent of laser cannons to bring down the entire platoon while he transported himself and Ra'ad up to his ship. Just as he was about to make a jump to his home planet of Osmos V, the lead Plumber of the ambush used one of the downed ships to take out the hyperdrive of Aggregor's ship. Unable to leave the planet, Aggregor had to come up with a new plan. When Ben and his team tracked his ship, they were attacked by Aggregor's robots. When Ben as Lodestar boarded the ship, it self destructed. Fortunately, Ben was able to survive thanks Lodestar's magnetic abilities pulling him back together. Meanwhile, Aggregor broke into Los Solodad with intent on using the Entropy Pump from Professor Paradox's old time-traveling experiment as a replacement for the machine on his home planet he could not get to. Upon discovering where he was, Ben and his group stormed Los Soledad, charging through the remainder of Aggregor's robots. Needing more time, Aggregor used a mind control device to have the five Andromeda aliens attack Ben and the others. After being freed from the control, Aggregor instantly recalled the five aliens. When Ben's team confronted Aggregor, Kevin warned Aggregor not to go through with his plan, mentioning that absorbing raw energy causes Osmosians to go insane, which explains Kevin's criminal past in the original series. Aggregor however, refuses to believe it, claiming that the powerful Osmosians told that to the weaker ones to control them. Before Kevin could convince him otherwise, Aggregor blasted him then used the Entropy Pump to transfer the powers and abilities of the five aliens into himself. Ben as Humungousaur managed to stop the pump before it destroyed reality. Unfortunately, it was too late as Aggregor had completely absorbed the five aliens, transforming himself into his mutated state, a massive Andromeda Alien mutant named Ultimate Aggregor.

Continuing in Map of Infinity (Episode), Ben, enraged that he was unable to save the Andromeda aliens, viciously attacked Aggregor, demonstrating much more of Humungousaur's strength then ever before. At first it seemed that Ben had taken him down, and if not for Gwen, Ben would have greatly injured him. Unfortunately, Ben's attacks did nothing to Aggregor as he was invulnerable as Bivalvan's armor. Thanks to Galapagus' nature, Aggregor was also now immune to Gwen's manna attacks. Showing off his newly acquired strength, powers and abilities, Aggregor toyed with Ben's team and easily defeated them all, completely destroying Grandpa Max's nervous system in the process. After knocking Ben out with a powerful seismic strike that demolished most of Los Solodad in the process, Aggregor left, now able to travel through space under his own power. Azmuth then reveals that the reason Aggregor absorbed those aliens was so that he had the power to find the four fragments of the Map of Infinity, which will allow him to enter the Forge of Creation and obtain the most powerful force in the universe. What Azmuth doesn't reveal yet is that the "ultimate prize" is in fact a baby Celestialsapien which Aggregor plans to absorb to become omnipotent without the extra personalities of Serena and Bellicus (Dwayne McDuffie confirmed that baby Celestialsapiens are omnipotent but do not develop their multiple personalities until they are fully grown). In order to stop him, Ben and the others must keep him from getting at least one of the fragments. After going through a temple filled with booby traps on Mykdl'dy, a fire/ice planet, Ben and the others nearly reach the first piece, but due to Ben and Kevin being forced to hold up the door that leads to the chamber holding the piece and Gwen being hit by a poison dart, they were powerless to prevent Aggregor (who used the trio to discover the traps and lead him to the first fragment) from escaping with the first fragment of the map. Despite this loss, Ben vows more than ever to make Aggregor pay for his crimes.

Aggregor appeared again in Deep, where he invaded the core of Piscciss to steal the second piece of the map, which was in the form of the planet's anti-gravity generator. With the ocean planet falling apart, Ben had no choice but to save the planet with Goop and let Aggregor escape again.

In Where The Magic Happens, the trio chased Aggregor to the Door To Anywhere, which Aggregor used to enter Yahwahtacsip. Gaining the assistance of Charmcaster, the trio entered the realm of mana to follow him. When the group was caught in a battle with Adwaita, Aggregor used it as a diversion to attack Adwaita from behind and steal the Alpha Rune from him, the third piece of the map, before thanking Ben for helping him again and disappearing out of the realm. With only one more piece left, Ben becomes more determined than ever to stop Aggregor before it's too late.

He reappears in Perplexhahedron, where he enters the Perplexhahedron, which was built by Professor Paradox to protect the fourth piece of the Map of Infinity. He uses the map's other pieces to enter the planetoid and makes his way through the maze, where he encounters Gwen and leaves her to freeze in an snow room. He finally makes it to the fourth piece but has a battle with Ben, who turns into Ultimate Cannonbolt. Despite his best efforts, Ben is beaten and loses the final piece to Aggregor, who escapes the crumbling planetoid, now possessing the key to entering the Forge of Creation. Despite losing the battle for the map, Ben and the others vow to win the war by stopping Aggregor once and for all.

Later, in The Forge of Creation, Aggregor attacks both Bens, Kevin, and Gwen in the Forge of Creation and easily defeats two of them, leaving the Bens to fight him. 16 year old Ben turns into Ultimate Swampfire and summons vines to hold him in place while 10 year old Ben transforms into Stinkfly and shoots goop at him. Aggregor breaks free and knocks down Stinkfly, who transforms back into young Ben. He shocks Ultimate Swampfire, who turns back to Ben as well. Young Ben offers his Omnitrix to Kevin who can absorb the energy and fight Aggregor, but Kevin instead absorbs the energy from the Ultimatrix, creating a blue energy sphere surrounding the area. Aggregor enters and prepares to absorb the newborn Celestialsapien, but is stopped by Kevin, who has transformed into a horrific massive mutant, towering above Ultimate Aggregor. Kevin assaults Aggregor with his multitude of powers and absorbs his energy (like Aggregor did to one of Galapagus' friends), transforming him back to normal and leaving him unconscious. Though Kevin, gone insane for absorbing the Ultimatrix energy was about to kill him, he is persuaded to spare his life by Gwen and the Bens.

Dwayne McDuffie confirmed that after he was defeated by Kevin, Aggregor was taken into custody by the Plumbers.

Appearances

 * Fame (first appearance)
 * Escape From Aggregor
 * Too Hot To Handle
 * Andreas’ Fault 
 * Fused
 * Ultimate Aggregor (Ultimate in the end)
 * Map of Infinity (Ultimate)
 * Deep (Ultimate)
 * Where the Magic Happens (Ultimate)
 * Perplexahedron (Ultimate)
 * The Forge of Creation (Defeated and loses his powers when Ultimate Kevin absorbed them)

Trivia

 * It's strange how Ben said that he's use the powers of the Andromeda 5 to save them when he never used any Andromeda alien on Aggregor (although he used Terraspin to fight Aggregor's soldiers).
 * Aggregor's name has been used in 2 episodes: "Escape from Aggregor" and "Ultimate Aggregor"
 * Aggregor has none of the previous villains weaknesses (except being mad with power). Instead of sending his henchmen like the Highbreed, he prefers to carry out the tasks himself. He always thinks his plans through, unlike Darkstar. Like Vilgax, he is arrogant but not enough to underestimate his enemies and has the power to back up his threats.
 * Aggregor has appeared in one season more times than any other villain, or recurring character, with a total of eleven appearances in Ultimate Alien: Season 1.
 * Aggregor's appearance is very similar to a Zabrak (more specifically Eeth Koth, Agen Kolar, Savage Oppress, and Darth Maul) from Star Wars. It is possible Aggregor's appearance is based on a Zabrak.
 * According to Dwayne McDuffie, Aggregor is a much, much greater threat than Vilgax (although both never met), even before he absorbed the powers of the five Andromeda aliens.
 * Aggregor refers to Kevin, a fellow Osmosian, as a "hatchling", a reference to their difference in age, power, and experience.
 * Aggregor has been shown to be a dangerous enemy, not even the Plumbers' are able to stop him. He has been shown to be capable of defeating Plumbers of any known rank (he even murdered Magister Prior Gilhil). He also seems to show little fear of the Plumbers (though at one point he tried to avoid conflict with them) or possible retribution by the Plumbers entire organization for his crimes.
 * It is interesting to note that the five aliens he kidnapped have powers/appearances based on the five elements: Water, Wind, Fire, Earth, and Lightning.
 * Aggregor's plan to absorb all the powers and abilities of the five Andromeda aliens is similar to Kevin's plan in the original series to obtain the powers of Ben's original ten alien forms (which unfortunately had disastrous results). Despite having at least eighty-nine more years of experience than Kevin, Aggregor's form after absorbing the five aliens is still amalgamated albeit far less grotesque and not lacking the full potency of the five aliens' powers, a result of a special machine he used.
 * His name come from the word "aggregate," which means to form a collection from different parts, a very likely reference to his plan to absorb the full powers of the five aliens he captured and later his Ultimate Aggregor form.
 * Aggregor said in Fused that his spear was designed to face electromanipulative species.
 * In the game Cartoon Network: Fusionfall There is a code set that comes with a Ultimate Aggregor Mask.
 * Aggregor wanted to obtain the omnipotence of a baby Celestialsapien because the personalities of Serena and Bellicus had not been developed yet.
 * Aggregor is the second villain to defeat a Ultimate, the other being Psyphon. Although, he was the first to defeat two Ultimates (Ultimate Cannonbolt and Ultimate Swampfire).
 * He is mentioned in cosmic destruction by Psyphon saying that he considered working for Aggregor but he preferred to work alone. Also in the same cutscene Psyphon said: "and look where it got him". However in order for this to work, the game's events would have to take place after season one of Ultimate Alien or The Forge of Creation.
 * Kevin reverted the mutation of Aggregor, despite that Osmosians can only absorb 1/10th of the abilities of an alien (regardless of how much energy and DNA they absorb from that being), whereas Ultimate Aggregor had 10/10ths of power of the five Andromeda aliens. This was because he used a machine to turn them into pure energy, allowing him to gain the full power of the aliens (confirmed by Dwayne McDuffie) and Kevin absorbed this energy.
 * His Toon Cricket Team's name is Aggregor Aggressives.
 * Each power was chosen for a specific task or power on Aggregor's search;
 * P'andor's heat and cold inmmunity on Mykdl'dy.
 * Ra'ad's electrokinesis, Bivalvan's hydrokinesis, aquatic agility, and underwater breathing, and Andreas's geokinesis on Piscciss.
 * Galapagus's mana resistance in Ledgerdomain.
 * Bivalvan's invulnerability, Andreas's strength, and Ra'ad's levitation for all situations.
 * All powers to survive the Perplexahedron.
 * In his first appearance, Aggregor had six horns; In all his other appearances, he had only four.
 * Dwayne McDuffie denies that Aggregor is a high ranking official or dictator of Osmos V when asked in the forum, since he owns a spaceship and robot minions. How he gets those is unknown and Dwayne just said "wait and see".
 * His name could come from aggressor, which means an invader.