Nega is a combination of Bowser Jr, Dimentio, Link, Dark Fawful, Princess Shroob, Dr. Nega, and Dr. Finitevus. Nega the user has been at Lemmy's Land more than most others, having found the site around the age of 9. Nega is Scipia's master and ruler of the Shroob planet, but most of the time he sticks around with the heroes to help. He was formerly an anti-hero and a villain but has now joined the heroes to fight in the war. After dying in combat with Positron, he schemes to find a way back to life and end the life of Malachite, the man who is engaged to Scipia.
Nega is very unpredictable, having constant mood swings and random actions. He's mostly comical, annoying, or psychotic, but can get serious when fighting enemies. Being made out of seven people, Nega can go from an immature child to an evil mastermind in seconds. When he was a main antagonist, he was extremely intent on reaching his goals and satisfying his needs. An incident in the past involving legions of zombie penguins and exploding skeletons has caused Nega to lose the feeling fear, so he has the guts to stand up to global threats like Kieron and Stygi. However, this led to his death, as he took on the challenge to fight the specifically anti-Nega Positron and was killed for it. He's nice around his friends... most of the time.
Not much is known about Nega's past. He was formerly known as Dark, due to it being his chosen title as he got it from Dark Fawful. Around 13 years after his fusion, he became fascinated by the anthropomorphic animals of the planet Mobius. Leading a team of scientists, the boy prodigy explored Sky Sanctuary and found the remains of the magnificent robot Mecha Sonic, which was still supercharged with Chaos energy after being destroyed by Knuckles the Echidna. Dark took back the robot, rebuilt it, and reprogrammed it as Hedgedark, his loyal robot servant, which guards his castle on the Shroob planet to this day. During another exploration in Mobius, he learned that the witch Cackletta hadn't really been killed by the Mario brothers and had been warped to Möbius, where she possessed one of Eggman's old robots and attempted world domination.
After a world war that lasted months, Dark defeated Cackletta and learned a greater extent of his powers, and Cackletta was amazed by his skill and promised to mentor him if he spared her. Accepting, Dark allowed her to possess Sonic the Hedgehog. The trio of Dark, Cacklonic, and Hedgedark went on several adventures afterwards together. Wishing to add a fourth member to the team, Dark built Robo Finitevus, a mechanical minion of multiple purposes that obeyed all of Dark's commands instantly. He was more domestic and stayed to care for the Shroobs while the trio was off having fun.
Around this time, 15 year old Dark visited Pokeplitrule, the world of Mario, Zelda, and Pokemon games. He befriended many residents there, including Chatot Paratroopa, Pinky the Kirby, Pyro Guy, Soft Spiny, Loxo the Duplighost, Flifit, and Green Snifit. They had their own misadventures together for a period of time. There was an entity on Plit known as Some Random Guy, a troublemaking trickster demon of pure evil that escaped from Hell. He harassed Dark and his friends for a while, as well. On a journey back to Mobius, Dark found a dying Lynx with amnesia and decided to repair him with cybernetics, dubbing him Jonny. He brought Jonny along with him back to Plit as a true fourth member of his team.
Eventually, the Plit-originating friends split up and went their separate ways upon learning of the disappearance of "Lemmy", the man who had brought them all together. Dark stayed behind with Cacklonic and Hedgedark, and this paid off as he had befriended Gengar, King Boo, Josh, and Shiny Arceus, other people brought by "Lemmy" who had not left after his disappearance. This is when some major villains started rising, such as the Steven Force and Shade.
Gengar, Josh and Shiny Arceus began coming less and less, but then Kaza, Buddy, Scipia (Then known as Dusky), Flyer, Rotom, Magikoopa, and others came along and befriended Dark. Dusky, being a Pokémon, was sought after by Magikoopa and Dark, but it was only after catching Dusky that Dark realized how unilke other Pokémon she was. Raising her into a Dusclops (and then nicknaming her Duscloper) Dark developed a closer relationship with her. As the main villains arose and attacked the peace, the group of friends rose against them, and Duscloper soon became a Dusknoir named Darknoir (after Dark himself) and Dark consumed her pokéball to keep her from being stolen by Magikoopa, who kept trying relentlessly.
After seeing how good a soul she was, defending innocents from the vile villains of the day, Dark began to feel infatuated with her, but decided to keep it secret, for how would his friends react so such an inter-species romance? Pokémon were treated as animals and pets, never intimate partners. However, Darknoir soon let slip that she returned his feelings, so he admitted them openly. Unfortunately for him, many, many people began to struggle with him for the love of Darknoir since she could not be rude and decide one over the rest. (That conflict continues to this very day.) As more and more villains were locked up, the world seemed to return to peace. Except, of course, for Dark and the competition for Darknoir's love.
Enraged by the indecisive results that she gave to them day after day, Dark began formulating a scheme on a universal scale: Rewrite time and space, change the world into a place where only he would be the true love of Scipia. He began to send her and her friends on increasingly dangerous missions to achieve this goal, forcing them to bring him many legendary Pokémon and artifacts of power that would help him release a Genesis Wave, a distorting ripple through time and space meant to help him achieve his goal. He kept this goal a secret and became increasingly frustrated and furious with the delays and failures that kept him from achieving his plan, to the point where he began to physically abuse Scipia and her friends.
After many months of their hard work, Dark revealed to his 'friends' the true purpose and meaning of what they brought him. However, at this time, the malevolent creature Chaos began expanding and absorbing more and more water and chaos energy while the heroes focused on internal conflicts. Chaos began travelling to other worlds, dimensions, universes, draining them of water and chaos, expanding himself into a massive destructive monster that began wrecking worlds he even made contact with. When Dark was ready to hit the big red Genesis button, the heroes attacked him, intent on stopping this resetting of time and space. Chaos returned to Pokeplitrule at this time and destroyed the planet just after the conflict warped into the Shroob Castle on the Shroob Planet. Refugees from Pokeplitrule stowed away onboard, most of them being old villains that then began to join the fighting. The castle then shot off into space as Dark saw Chaos was expanding through the universe and quickly approaching the Shroob planet. As the castle flew through space, just ahead of the spreading destruction from Chaos, Dark finally got to his Genesis button, resetting the universe.
Unfortunately, the Genesis Wave was a failure in that it failed to stop Darknoir from having affection from others, causing Dark to realize that all his work had been for naught. Deciding instead to conquer the world and enslave his former friends, he built up an army consisting on soldiers form many similarly reset worlds and viciously attacked the amnesiac heroes. They held off and slowly began to regain memories of the old world, but then Dark realized a major flaw in his plan; he had never been the King shroob in this world, and due to this, at this very moment the warmongering Elder Princess Shroob ruled the Shroobs and was ready to drop the Lightmass Bomb on it in revenge for their previous defeat. Deciding to save his skin Dark built himself a new flying castle to escape the destruction and go join the reset Shroobs, but just at that moment, the remaining heroes launched their final attack on Dark and boarded his castle. In one last push, sacrificing the lives of many of them, Darknoir and co. finally got through him and undid the Genesis Wave, sending them all back to Pokeplitrule, where it turns out that by undoing the Genesis Wave, the heroes had undone the events leading up to it and thus managed to stop Chaos in his basic form.
His plans ruined and the competition for Scipia's heart ongoing, he changed his name from Dark King Shroob Jr. to Nega Link King Shroob II, trying to deal with the disappointment of all his work going to hell. In the fixed world, however, Grodus attacked, taking over a big city and assaulting the heroes. Deciding to win back their favor, Nega allied with them, and, with help from their old friends Chatot and Pinky who had suddenly returned, Grodus was defeated.
The real mastermind behind Grodus was revealed to be Omega, a colossal warrior robot from the world of Megaman, and Omega used his massively powerful robotic army to wage a global war. With help from Yoshino, his armies from Lavalava, and the gigantic weapon Yoshino built into Mt. Lavalava, Omega was defeated. Shade returned with an alliance to all of the previous enemies faced by the heroes and struck at Lavalava, taking it over and making it his capital from where he ruled a global empire built from the power of his men and the remains of Omega's.
The heroes began freeing the world from Shade, one country at a time. Meanwhile, Darknoir had turned human and Nega had renamed her Scipia. As the heroes progressed around the world, repelling the villains, the Chaos Council arose, a team of brainwashed villains from across the multiverse, controlled and led by a vengeful Chaos and an alternate dimension version of Nega dubbed Dark Nega that came from the same world as powerful hero Echo. Scipia's true origins began to be revealed, along with those of her brother Stygi and the strange alien villains that began appearing in the heroes' path. Taking up a simulatenous triple war against Shade, Chaos, and the alien overlord Haydn, the heroes were forced to ally with Stygi and his mysterious alien mentor Kieron, along with their diabolical creations.
Nega continued to fight alongside the heroes while struggling for Scipia's heart. One day, however, a man from the future that worked for Shade named Eobard was sent to kill Nega. Accepting to take him on in battle, Nega fought against the man from the future, who revealed a suit of armor made specifically to defeat Nega. Dubbed "Positron", the suit deemed effective and after a massive and destructive battle to a heavy metal song through the snowy wastelands of Ice Land, Eobard finished off Nega, ending the life of the confident king.
As a ghost, Nega finally had time to relax and think about his next scheme. During a period of the war that took place against the traitorous shroob Steven, Nega returned in the body of a random Gengar and attempted to murder Itachi, but failed and got himself killed again. Upon the completion of his latest plans, Nega set out to ally with Sasori to assassinate Malachite, an alien prince who forced Scipia into marrying him. Nega currently awaits the right chance to return to the living and double team Malachite with Sasori.