Xicor, also known as Zaiko, is the main antagonist of Toyble's Dragon Ball AF. He is the actually the youngest son of Goku, due to deceitfulness and trickery casted by the vengeful Western Supreme Kai. Thus making him part Saiyan and part Kai. *A Saiyan God* in other terms. Xicor goes to Earth years after Son Goku's departure with Shenron, with his mother, to seek out the strongest, gain position of ruler of the Earth, and to meet his father.
Xicor doesn't seem to resemble any of his siblings, probably due to the fact that he has a different mother than Gohan and Goten. He is a white male with silver hair and 2 black spikes in his hair. He also has two black spikes protruding from his chin. He sports a green gi and black shoes. He also wears green wristbands and has a red outline under his eyelids, similar to a Super Saiyan 4.
After Frieza's defeat on Namek, Goku was on his trip to the Yardrat planet where there Goku met "Princess Lila" (Western Supreme Kai). Goku was given a feast which later caused him to feel tried, prompting him to sleep. Using this opportunity, Lila steals a sample of Goku's DNA to create a ultimate being, Xicor. Lila soon makes her debut, along with Xicor, as the first antagonists of DBAF after Omega Shenron's defeat.
Dragon Ball AF:
While Goten and Uub were stopping Pilaf and his gang from robbing a bank, two space pods landed in a wasteland, with the Western Supreme Kai emerging with her son Xicor. The two immediately head to find Earth's greatest power and come across Goten, whom they nearly kill and causes a great shockwave around the whole planet. Gohan senses the power and comes to his brother's aid, questioning who Goten's attackers are.
Xicor reveals himself as Gohan's brother and son of the Western Supreme Kai, greatly shocking Gohan. Vegeta and Trunks arrive as well to combat the invaders. Xicor then demonstrates his power by destroying half of the Earth. An enraged Vegeta battles Xicor but despite his Super Saiyan 4 transformation he is no match. As Vegeta is pummeled, Gohan's tail suddenly appears and Gohan transforms into Super Saiyan 4 (his tail regrew somehow and achieves this transformation while training). Super Saiyan 4 Gohan, Vegeta, and Super Saiyan Trunks battle Xicor but despite their combined power and Gohan's attempt to call Goku, they are ultimately no match for Xicor and waste all their power.
With all their energy exhausted, the heroes stand no chance against Xicor. However, before Xicor can act again, Kibitoshin appears and attempts to seal Xicor with the "Kai-Kai Divine Sealing Wave" into the Z-Sword, but the Western Supreme Kai intervenes and manages to prevent the sealing.
Before Xicor can destroy the sword, Gohan picks it up and attempts to attack Xicor with it, but is actually distracting him, buying time for Dende to restore Kibitoshin's strength. Kibitoshin attempts to seal Xicor once again and despite Western Supreme Kai attempting to interfere once again, they succeed. The Western Supreme Kai, in a fit of rage attacks Kibitoshin and Dende, then attempts to release Xicor from the Z sword. Just than Vegeta stands before Western Supreme Kai to stop her from releasing Xicor. However the higher class Kai proves too much for the weakened Vegeta and is defeated. But while the Western Supreme Kai is distracted by Vegeta Kibitoshin grabs her from behind with a full nelson. Kibito Kai than teleports the two of them to another planet where Kibitoshin self-destructs killing himself and the Western Supreme Kai.
Kibitoshin though did the sealing technique incorrectly, thus causing Xicor to be heldwithin to Z sword in only 1 month. Knowing this, Old Kai tells the Z fighters and their siblings to make preparations to revive Goku out of the Dragon Realm. In order to do this, they needed 7 Super Saiyans to cast their light onto the Dragon Balls (which were turned into stone after Goku went with Shenron to the Dragon realm). Vegeta claims that they don't need Goku and that he can handle him alone. Trunks disagrees with this and goes to Planet Namek with Goten to revive Broly so he can provide help against Xicor and the process of bringing back Goku.
Broly questions why he is alive and on Earth when he finds Vegeta in front of him, causing him to react insanely and charges at Vegeta. He is obstructed by Gotenks and is easily outmatched. He is taken to Capsule Corps, where later on he escapes and is obstructed by Pikkon. Trunks and Goten gives up and goes off with Vegeta to train in a similar device like the Hyperbolical Time Chamber.
One month has past and Vegeta and Trunks, plus Mr. Satan and Krillin, awaits for Xicor to come out of the Z sword. Xicor does so with the same insane Ki level, replying to the Z fighters that they will die. Vegeta contradicts what Xicor had said and responded that he will dispose of him now. A battle erupts with Xicor using Instantaneous Movement to approach Vegeta, with Vegeta blocking Xicor's attack and punches him down a mountain. Vegeta preceeds to pummel XIcor, which Xicor questions why and how he got so powerful in such a short period of time, which Vegeta promptly says that the level he is at now is 5x what Xicor had faced before. Xicor get aggravated at this and goes up to full power, blowing away Krillin and Trunks, even shocking Vegeta.
A scene later after this (the manga is still on-going) is with Goku arriving at the battle field and Goku declares that there is a form even beyond his SSJ4, to which Goku begins to power up. The enormous ki that was now emanating from Goku's body shook the whole cosmos and blew Xicor away with immense force. A newly transformed Goku amazes everyone and even scares Xicor for brief moment.
Super Saiyan 5
Not exactly a SSJ5 but he is shown to be stronger than SSJ4, after he dominated Vegeta and Gohan easily. He also has a few characteristics of being a SSJ5, such as his silver hair and immense strength and speed. Xicor never shown any transformation so far in the manga except displaying his insane power to the whole Earth.
Being half-Kai and half Saiyan and being son of Goku, Xicor is one of the most powerful beings in the universe. When Xicor makes his first appearance in Dragon Ball AF, he was shown to effortlessly destroy half of the Earth and defeat Goten with only a Ki Blast. He also completely out-classed SSJ4 Vegeta, SSJ4 Gohan, SSJ Trunks, and Kibito Kai prior to his imprisonment. Even Vegeta, who trained for 5 years in a similar Hyperbolical Time Chamber just to defeat Xicor, was still down on his knees due to Xicor's power. Not only that but defeats Goku in his SSJ4 form, which prompts Goku to transform into a SSJ5. Because of Xicor's relation to a Supreme Kai it is possible that his ki is divine like a Supreme Kai's, possibly placing him in a permanent passive Super Saiyan God form. This could be the reason for his immense strength and capability to handle SSJ4 Vegeta and SSJ4 Gohan in only his base form.
Xicor is often seen being arrogant and views all life forms with low power levels as pathetic. He is nothing of his brothers or his father's personality, nor does he even care a slightest bit about them (Seen when he did not hesitate at all when he blasted Goten to the Earth or when he was engaged in combat with Gohan. However, he does seem to have respect over his father, Goku, even going to Earth only to meet him (though he may have just wanted to kill Goku just to his "position"). The impure, evil son of the mighty Saiyan also brags about being the perfect being he claims and declares that he will be the heir of Goku over the universe. The truth in reality is that Xicor seems to be misguided, due to being told that Goku was often boasting of his powers and that he ruled over the whole universe. Gohan tried convincing Xicor that what he says his not true but the Western Supreme Kai just changes his mind, saying that what these "insignificant pests" say are lies.
(Xicor to Lila after arriving to Earth) "I, Xicor, am heir to Son Goku, the most powerful fighter in the universe!"
(Xicor to Gohan, who had just arrive from the battlefield) "Are you Son Gohan? Why is you power lower than mine?"
(Xicor to Gohan) "Me? Why I am your little brother! Son to Goku!"
"More of them aye? Saiyan that is."
(Xicor to a pummeled Vegeta) "How does it feel to be dominated?"
(Xicor talking about Trunks's intrusion) "What? You can't even follow my movements with your eyes? Your are a pitiful disgrace if you are a Saiyan!"
(Xicor after taking a hit from Gohan) "So you finally decided to fight Gohan? Come at me."
(Xicor exhausted after nullifying the combined efforts of Gohan, Vegeta and Trunks) "You..I-I may have not perished but I am getting there. No more miracles for all of you. Who shall die first?"
(Xicor after finding Gohan and Kibito Kai on a mountain) "Hahahahaha-Saved by the East Kaioshin have you Gohan! Hahahahahahah-as I said earlier, there is no escape for you now."
(After one month of imprisonment in the Z Sword, Xicor to Vegeta, Trunks, and Krillin) "You all shall pay..."
Xicor is said to resemble a SSJ5 in a few ways. One being its eyelids, another is the same crazy silver hair. In some translations of the manga, it is said that Xicor himself is a SSJ5! Whether this is true or not, a fact that goes against this response is that the Western Supreme Kai/Lila (Xicor's mother) possesses a similar hairstyle with gray. He presumably inherited these traits from his mother, as he does not posses the fur or the tail that are require in this form.
Xicor is one of the few villains in the Dragon Ball Universe who do not have the desire to collect and use the Dragon Balls.
Though having characteristics of a SSJ4 and a SSJ5, there is no evidence of him being one. He may not even be a Super Saiyan, though he has power far beyond one.
At one point of time, Xicor actually experience FEAR, when Gohan was about to seal Xicor away in the Z sword with the help of Kibito Kai.
Even when it has been stated that Xicor is the youngest son of Goku, there is a chance of Xicor actually being older than his brother Goten. This is a more likely answer because Lila got a sample of Goku's DNA after the defeat of Frieza, which was prior to Goten's birth at the end of the Cell Games Saga. He also seems to attain the appearance of being at the same age as Gohan or even his father.
Xicor also appears as an antagonist in an animated series called Dragon Ball Absalon by Mellavelli. In here, he is shown in the opening, fighting Goku and appears to be a "Super Saiyan 6".
Rigor, the Central Antagonist of Dragon ball New Age, is shown fighting Xicor in one of Malik's deviations in Deviantart. Though it is just artwork, Malik had displayed Xicor and Rigor in an intense battle, with both of them wearing each other out. XIcor is shown giving Rigor a hard time, with Rigor doing the same. MALIK may had done this just to make a decent looking artwork, but he could have also chosen to make Xicor like that as he has positive views of Toyble's AF. This artwork may also adds to the fact that XIcor's power may be on par with a Super Saiyan 5's.