VexVex is a main protagonist of New Beginnings and the Legendary Super Saiyan of Universe 14. After many adventures, he has become close allies with a good deal of Earth's inhabitants.Vex shares complicated relations with the other protagonists of Universe 14.
"I am Vex of Universe 14! I am rivaled by none! No one dares to call themself my equal, and anyone who does will be squandered by my might! I am the prince of Kalijiki, I am the Legendary Super Saiyan, and this is where you meet your end!" - Vex eliminating Xevin from the Universal Survival Tournament
Vex is harsh, he is almost always shown to be ruthless and uncaring, however it is shown time and time again there are things he does care for, his planet, his home Universe, and all of his friends.
Not much is known about Vex's background other than that he was raised on Planet Kalijiki under the King as a prince, and he had two brothers who hated him Hex and Lex. He travels to Planet Earth to try and rule it to impress both his father and his brothers, but he fails too, and eventually he is convinced to work together with the heroes, which leads to his brothers attacking and begins the process of Vex defending Planet Earth and joining the Universe 14 Z Fighters.
Attack of Kalijiki
Vex is the cause for all of Kalijki to be attacking Earth, it started with Hex and Lex working together to try and take everyone down, and they almost succeed until Ken turns Super Saiyan and when it looks like Ken is about to win, Hex and Lex fuse into Helex, causing mayhem and turning the tables once again. However due to the guilt he feels for Hex and Lex arriving and the rage he feels at himself for never being able to best them, Vex too awakens into a Super Saiyan and together Vex and Ken take down Helex.
Upon hearing the news that two of his sons are dead and the only one left alive has betrayed him, King Ikora himself steps down from his throne to attack Earth himself. Vex, Ken and the rest of the Z Warriors tear through his army and eventually face the powerful King himself, it is only through Ken's Super Saiyan 2 transformation that they win.
The First Ancient: Seru
After failing to defeat the King himself, Vex runs off by himself into space to grow stronger so that he can defend the planet himself. However while he is gone Seru the first Ancient awakens from his long time slumber. Ken manages to put up a great fight against him, but the tides turn when Choken is absorbed and Ken starts to get pummeled until Vex lands. Vex, having attained SSJ2 tries to defeat Seru but also loses. Ocari gets both of them out of there and teaches them a technique that will allow them to contest with Seru: The Fusion Dance. After recovering and practicing the technique, Vexen is born and finishes Seru.
Before he dies, Seru warns them the Ancients will avenge him.
The Legend Awakens
Vex having run off by himself after the fight with Seru, begins to feel unorthodoxly ill and talks to the others about it, Ocari watches over him as Ken and Choken go to find a cure. During this time Vex awakens into the Legendary Super Saiyan and nearly kills Ocari before Ken and Choken return. Vex also nearly kills both of them too and almost destroys the planet before he regains control and manages to stop himself.
Dr. Wheelo's Cyborgs
Vex and the others defend the planet from Dr. Wheelo's incredibly strong Cyborgs. Eventually Vex and the others get captured and are locked inside the laboratory, during this time Ocari turns into a Super Namekian and frees them. As Wheelo's Cyborgs scour the Earth, Vex and the gang jump the cyborgs and Dr. Wheelo is among them and through the fusion of Ocari and Ken they almost manage to defeat Wheelo however the fusion runs out. It is through the sacrifice of Vex's life that Wheelo is thought to be defeated. However it is shown at the end of the arc that Wheelo is alive and he collects Vex's blood.
Eventually Vex is revived with the Dragon Balls after a long year of waiting. When he returns, Ken and Choken explain how they started a Martial Arts school and asks if he'd like to join them, when he declines he runs off into the mountains to train again. However one student is clearly much stronger than the rest as Ken and Choken soon find out. His name is Kaneki and none of the students are able to compare, and he even manages to contest with SSJ2 Ken.
However one day Kaneki feels deathly ill and his hair constantly flickers between green and his normal brown. Before he transforms he explains how he was captured by a scientist (Dr. Wheelo) and had blood samples put into him and ever since then he's been much stronger. He awakens into the Legendary Super Saiyan and begins his rampage and even Vex shows up to try and stop him. Eventually however, Kaneki manages to calm down and he passes out.
After this, Vex takes Kaneki as his own and trains him by himself.
Vex yet again in the mountains, but this time he's not alone and is with Kaneki. However once again he feels ill, but this time he attempts to challenge it thinking he can control the Legendary Super Saiyan form. As the form awakens it looks like Vex won't be able to control it, but he manages to pull through and control the form. As he's about to practice training with it though it doubles in strength in what is known as Legendary Super Saiyan 2. This time Vex is unable to control it and he rampages into the city and starts destroying everything until the Z Fighters show up.
The Z Fighters are much more of a match for Vex this time and give him a run for his money, it appears as though Vex is about to lose to SSJ3 Ken and Choken, until however his power doubles once again into Legendary Super Saiyan 3, and once again he takes complete control of the battle, it is through the death of Ocari that Ken decides what must be done and he blows himself up in an attempt to stop Vex.
However Vex is not destroyed as thought and has reverted to Legendary Super Saiyan 1, and through the combined efforts of Kaneki and Choken, Vex is finally put down once again.
Showdown Against Universe 13
When Vex is revived he continues to train Kaneki and during this time he is finally able to control both his Legendary Super Saiyan form and his Legendary Super Saiyan 2 form. Once again, West City is under attack. However this time it's from other Saiyans from Universe 13: Ryu, Resurken, and Kurzin who Ken and everyone else can't even land a hit on. Vex arrives with Kaneki and everyone is about to be killed until suddenly Vex risks it all and turns into the Legendary Super Saiyan 3. In this form he is able to compete with Ryu, however going against him, Resurken, and Kurzin is too much for him, and everyone is forced to retreat.
When they retreat they try to come up with a plan for everyone else to gather more power, Ocari is about to tell them of one rumor he knows of, when suddenly huge power spikes appear at the beach. The gang flies over and a group of unknown warriors are slaughtering the nearby city. They drive them back to the beach when they realize that they're fighting the Ancients that Seru warned them about, Vex again is the only who can compete but by himself he can't defeat all of them.
Realizing how worthless he's been and boiling all of his anger together, Choken gathers up all of his energy and awakens into a Super Saiyan 4, with the combined efforts of him and Vex they manage to defeat the Ancients. The Z Fighters return to Kame House and Ocari tells them of the rumor he knows of the "Super Saiyan God." He explains a ritual and together everyone pours their energy into Ken and he transforms into a Super Saiyan God. During this time, Supreme Kai seals Kaneki's Legendary Super Saiyan power into his base form and Kaneki now can always access that power into his base form when needed.
The Z Fighters all meet up again and charge directly into combat, this time pushing a much harder force. Together they manage to defeat Ryu, Resurken, and Kurzin. Froxaz pools all of his energy into one final Supernova that he tosses into the planet in a desperate attempt to kill everyone. However with Super Saiyan God Ken, Super Saiyan 4 Choken, Legendary Super Saiyan 3 Vex, and Mystic Kaneki, they manage to push the ball back and kill Froxaz.
Ryu, Resurken, and Kurzin wake up from being controlled and apologize. They meet up with Choken again and are about to head out to their universe again when Kaneki asks if he can join them. This brings mixed feelings of sadness and anger into Vex.
Vex has the ability to transform into a Legendary Super Saiyan (LSSJ), he is the only one in Universe 14 who has this power naturally attained (Kaneki having achieved it from Vex's blood). Vex has also been able to increase his transformation to LSSJ2, LSSJ3, and even LSSJ4.
He can also turn into the Unified Legendary Saiyan (ULS) which is his ultimate LSSJ form from his own power. However using God Ki he has one form that is more powerful: Legendary Super Saiyan God (LSSJG). It is Vex's ultimate form, and the power is incredibly difficult to control, however Vex uses it to compete against the other universes in the Universal Survival Tournament.
Ken Generation of Universe 14, Universal Tournament, and Universal Survival Tournament.