Zero began his true work when the Krizalid project had begun. Acting as the project supervisor, he was to monitor all actions done by Krizalid, and also analyze the performance of K', who is a human being infused with Kusanagi power. After Krizalid was defeated, Zero was the ominous voice who talked to the heroes of the battle. Zero considers Krizalid to be a worthless agent, and dispatches him by launching a huge boulder over Krizalid. After proclaiming the superiority of NESTS, Zero retreats to seclusion once again....

During one full year, Zero begins the fabrication of what should be the most fearsome weapon ever created by man: the Zero Cannon. A killer satellite that would orbit the Earth in outer space, it would contain a huge laser cannon that would be able to fire at any designated spot on the ground. But this type of destructive energy needed an equally powerful energy source. Using the same technology that was used for Krizalid's battle armor, Zero fabricated a power generator that would be able to absorb the fighting energy of any human being. The generator would then channel the energy towards the Cannon, and power it up enough for it to destroy whole cities at once. Not one, but twenty of these death machines were created. Zero knew these were weapons capable of wiping out any designated point on the face of the planet. But he needs someone outside the organization to launch it, to avoid suspitions....To accomplish this, Zero created a clone of himself that would assume another image, and infiltrate a local mercenary agency that would prove most valuable for his plans.

The Ikari Warriors proved to be the perfect target for Zero's evil plans. That way, he could avoid any possible investigation by his bosses. But there was no direct way to approach the mercenary squad. Zero, using the advanced clone technology of the NESTS cartel, created a clone of himself, and programmed him to pass as a fellow mercernary commander named Ling, who would lead the fighters straight into his trap. His plan would soon begin....

Taking advantage of the friendship between Ling and Heidern, Zero launches the Zero Cannon to outer space, saying that it would be a weapon to use against NESTS. After that, Zero suggests Heidern to organize a new King of Fighters tournament in order to attract NESTS out of their hideout. In order to do so, Zero advises that Heidern should follow K' and Maxima, former NESTS agents, who should be able to confess something about NESTS' whereabouts. While Zero fixes that situation, he also makes some movements on his side. He dispatches two of the most important agents that worked for Ling, and sends them to attract the former members of the fighters of the faithful battle one year ago. Seth and Vanessa are assigned to search out for K', Maxima, Benimaru Nikaido, and Shingo Yabuki, and bring them to Southtown for the final battle. Zero's plan begins as scheduled....

But NESTS has also moved their pieces. After sending the "anti-K'" Kula to stop Zero's plans, NESTS plans to wipe their trace in Southtown. Meanwhile, as the tournament advances under the happy gesture of Zero, the final battle in Southtown nears. After Heidern realizes that things aren't going as planned, Zero puts the final part of his plan into motion. He captures Heidern using his soldiers, which posed as Ling's soldiers, to stop Heidern from any further interference. Now, Zero prepares himself for the final match in a temple located behind an abandoned factory in the industrial zone of Southtown.

When Maxima and the others arrive with Zero, he tells them his malevolent intentions. He even used his own agents, Seth and Vanessa, as pawns in his maniacal game. He injected them with his own genetic code to enhance their abilities so they could perform better in battle. Facing the rage and anger of many of the fighters in front of him, Zero manages to get one step closer. The warriors are so angry that they will fight with no drawbacks. This will gain him enough energy to charge the Zero Cannon!

During the battle, Zero manages to display two styles: one of them was pure strength and speed, using his power and his razor-edged skirt. The second part of the battle, when things suddenly got serious, Zero used dark arts in order to surprise his opponents, and even use his own fighting aura to create chaos around him. After wiping out practically all the resistance, Zero declares himself the winner, but not before Lin stabs him in the back. Furious, Zero gives Lin a sound beating, but now he has to face K'. Zero feels that his body doesn't reply to his commands anymore. The stab from Lin injected poison into his body, downgrading his physical status, allowing K' to deliver the final blow.

Badly wounded and enraged, Zero is ready to activate the Zero Cannon, since it should already have enough energy to blow his enemies to bits. However, the generator does not respond to his command inputs. Suddenly, Zero is inmobilized, and two mysterious women, called Diana and Foxy, appear at his sides. They condemn Zero to death for trying to betray NESTS. Amidst his anguish and pain, Zero watches how Kula activates the Zero Cannon from outer space. The beam falls on the temple itself, and Zero receives the impact head on. In his dying place, Zero delivers Whip the project data, and watches over as Kyo and Iori engage in their faithful battle, before finally being buried by the debris of the falling temple, with Southtown as his crumbled tomb....

But the original Zero was still safe and sound in the main NESTS HQ. He was disgusted at the clone's feeble attempts to destroy NESTS. His superiors were shocked that Zero's clone would attempt such an outrageous action against their own organization. But Zero discarded the action as an individual action carried out by his clone. What was important now was to plan the scheme for next year, as the leader of NESTS intended to set out their primary plan to world conquest. The fighting data information had already been gathered and saved in the main database of NESTS' computers, so all that was left was to take care of all those fighters once and for all. This way they would ruin the world of the strongest fighters they had, leaving the planet hopeless! Zero was more than willing to clean his image to his superiors, but he noticed a funny way in which his comrade Igniz had been acting lately.

Zero was summoned by the president of NESTS as the King of Fighters tournament was well underway. There he was faced by Igniz, but said nothing to the president about his suspitions. The president of NESTS commands Zero to destroy the winners of the King of Fighters tournament as soon as possible, and tells Zero to take one of their rocket ships and lead them to their main HQ, where they will surely become guinea pigs for NESTS in their new world order. Zero accepts, and soon comes up with an idea to camoflage the ship as a mere blimp so it won't cause any suspition. Zero does so, and leads the winning teams into his own trap....

As soon as the teams board the blimp, Zero discards the blimp disguise, and sets the ship towards a new course: the main HQ of NESTS in outer space! Meanwhile, he walks down to the bridge along with his pet lion to face the winning team himself. He is pleased to see that it is K' and his partners who have arrived this far. Everyone is surprised to see Zero still alive, but Zero tells them about his treacherous clone. But this time, things would be very different since they would now face the original! But Zero knows that facing them alone would be a mistake. He summons the help of his sidekicks: a clone of Krizalid, which Zero had made from the Krizalid project data, scrapped 2 years ago. He also summoned Ron, who had bone to pick with Lin, one of K's teammates. He even pits his own lion into battle, as Zero comes face to face with K', and claims that he won't be getting away this time!

Zero indeed shows that he has a lot more power and skill than his clone, and it shows when he displays a great amount of force behind his techniques. But K' knows what he is going up against, having faced Zero's clone a year before. After a moment of letting his guard down, K' begins his assault, and Zero is unable to resist for too long. Zero is then defeated by K', as well as his sidekicks are defeated by K's partners. But Zero doesn't seem to take harsh decisions as his clone did. He just stands there, disappointed but calm. He admits his inferior technique, and notices that the rocket ship has finally arrived at the NESTS space station. Knowing what would come next, Zero tells K' and the others to keep on going, since the real fight has yet to begin. Then, Zero notices that the whole place is beginning to explode and come down in a heartbeat. Zero hurries the others, as he stands there with resolve. K' and his friends manage to escape, as K' bids farewell to Zero. Zero knows that whatever Igniz is planning, he won't get away with it. Zero stands tall to the very end, as the ship explodes and vanishes into the dark void of space.

The two sides of Zero are expressed in the 2 tournaments in which he took place in: one, his clone, which expressed his own ambition and desire to control NESTS and take over the world using the power they wielded. But his true self, although loyal to NESTS, is not evil at all. He is actually quite honorable, and likes to have a fair match. He will do anything for the cause of NESTS, and will not hold back against anyone. Zero pledges his alliance to the president of NESTS even during his final hour, as the true warrior he is.