Full Story Synopsis

A few days after the defeat of the Eggman Empire at the hands of Sonic and the Resistance, Dr Eggman makes a last ditch effort to regroup his forces, silently deploying Metal Sonic to return to the ruins of his fortress and retrieve the the Phantom Ruby, a tool he intends to use in his efforts to re-establish his empire. Upon making contact with the reality-altering gemstone, Metal Sonic is overwhelmed with its power, transforming back into Neo Metal Sonic. Having now been freed from his master's control, Neo Metal sets off on his own to Eggman's old laboratory to perform tests on the Ruby, in an attempt to overclock its power. While there, Neo discovers a mask-less, powerless Infinite being held in stasis, following Eggman's betrayal. Neo releases him, offering him the proposition of even greater power, and to exact revenge against the mad doctor and Sonic, to which he agrees. Infinite and Neo manage to create and harness the power of two overclocked Phantom Rubies, using their powers in secret to create their new Phantom Army from the ashes of the Eggman Empire. In their efforts to overclock and sustain the Phantom Ruby’s power, Neo reconstructs the Death Egg to house the newly created Phantom Ruby core, the source of the Ruby’s energy, which when fully charged will give Neo and Infinite the power to rewrite reality at will, a function that Neo plans to use to make himself the one true Sonic. Such power emanating would be enough to alert the Resistance to these activities, so upon the beginning of the core’s charging sequence, the villains’ plan to use their Phantom Army to bring an all-out war to the Resistance, a front that intends to distract them from finding the Phantom Ruby core.

Once activated, now with the growing power of the Rubies in their possession, Infinite strikes. He first targets Dr Eggman, which leads them to a battle in Green Hill, where Infinite uses his new found power to destroy his Death Egg Robot army, letting out an energy surge powerful enough to scorch the Green Hills into ash. This is almost immediately detected by Resistance HQ, with Amy calling Sonic to enlist his help to seek out this energy spike. Being nearby in Star-Light Zone, Sonic agrees and heads to Green Hill, only to find it a desolate wasteland. After traversing his destroyed home, Sonic spots Infinite facing down a vulnerable Eggman out in the open. As soon as he arrives, Infinite carries out his revenge, proceeding to banish the doctor into Null Space. Sonic is no match for the Ruby’s newfound power, as Infinite reigns terror upon him. He leaves the hedgehog alive however, continuing to toy with him, in which Sonic is then alerted by Amy that Sunset City is once again under attack. Infinite knows a much worser fate is in store for him, vanishing in a flash, leaving Sonic to race off to the city.

Meanwhile at the Chemical Plant, Team Chaotix have just finished clearing up the place of all the badniks that still resided in the area, securing the shuttle bay for the Resistance’s fleet. In that moment however, the group see what appears to be Infinite descend, who proceeds to tear them down. Before Infinite can deliver a final blow, the Avatar swoops in to save them, returning now a more seasoned Soldier. Infinite flies off towards the shuttle bay, and the team give chase, breaking down the new Phantom badniks that have appeared before them. They are too late however, when they arrive the shuttle bay has gone up in flames, with most of the resistance ships destroyed, a strategy intended to further prevent the Resistance from getting anywhere near the Phantom Ruby’s core. The group manage to find one remaining craft however, which they use to make their escape back to Resistance HQ. Upon their leave, Infinite watches from a distance, with the Avatar facing him down, noticing something slightly off about Infinite.

At this time, Sonic has just made it to Sunset City, currently under siege by the Phantom Army, with golems attacking all over the city. Knuckles radios in, telling Sonic that while the lower levels of the city are more under control, Resistance HQ is under attack from one of the golems. Sonic arrives on the scene and help the Resistance take down the ghoulish monster. Sonic continues to run about the city smashing any badniks that come in his way, with the Avatar and the Chaotix arriving shortly thereafter. The reunion is cut short, as another golem appears out of the ground, sending the group into disarray. Luckily they are saved by Tails, wearing his roboticisation armour he held onto from the Lost Hex. With the area becoming more treacherous, the group return to the Resistance base, meeting up with Amy and Knuckles, who are just as bewildered by the sudden re appearance of Infinite as they are. Sonic is confused as to how Infinite was both in Green Hill and the Chemical Plant at the same time, but before he can give it any more thought, they receive a radio transmission from a resistance squad out in Mystic Jungle, reporting a sighting of Infinite.

Sonic and the Avatar team up once again and race off to find Mystic Jungle seemingly experiencing a blizzard, an almost nuclear winter. Sonic and the Avatar save a handful of soldiers from a group of badniks, who tell them that there are other members still out in the forest. The duo continue to the higher parts of the forest, where they find a massive part of the forest being burned by a legion of Flame Breath badniks. They manage to reach the remaining soldiers, however it is revealed that they’re merely illusions conjured by Infinite as a trap to draw Sonic and the Avatar in, with the actual soldiers that came over the transmission being nowhere to be seen. Suddenly a second Infinite appears, with it seemingly being the one the Chaotix encountered at the Chemical Plant. This doppelgänger reveals himself to be Neo Metal Sonic, having used his power of Liquid Metal transformation to imitate Infinite and throw off the Resistance. With their intentions clear to destroy the Resistance, Sonic runs head-first into battle, leaving the Avatar behind, resulting in the two being thoroughly beaten by Infinite and Neo. At the tail-end of the fight, they use their powers to send the Avatar into Null Space too. In the commotion, Sonic breaks free and runs off, believing the Avatar has been lost. Infinite stands confused, assuming Neo wanted to finish off Sonic personally, but Neo, knowing that now there would be no chance of the Ruby’s core being compromised, sees it as a non-issue, and rather an opportunity to slowly break down the hero.

The Avatar however, when thrown into Null Space, is strangely redirected through to another portal, which drops him into the interior of the half-rebuilt Death Egg. The Avatar activates his homing beacon, which Sonic and the Resistance intercept back at their HQ. Upon doing some further deep-space scans, Tails determines that the Death Egg has been storing the Phantom Ruby’s core this entire time, having previously assumed that only the wreckage of the previous Death Egg remained. This prompts the Resistance to action, with the plan to gather their remaining ships for an all-out assault on the Death Egg, giving Sonic the opportunity to board the Death Egg, find the Avatar, then seek out the core. With the fleet approaching, Neo is taken aback, having calculated there being no outcome in which the Resistance would discover the existence of the Phantom Ruby’s core this soon. A fact of which that continues to drive a wedge between Neo and Infinite. Given the core has not reached it’s maximum power, they are in a vulnerable position, deploying countermeasures against the Resistance Army to give the core more time to fully charge. The Avatar listens in on all of this, and manages to pass on these findings to the Resistance.

Now the clock is ticking, as Sonic and the Avatar reach the core, using Tails’ flash drive to give him full access to hack into the Phantom Ruby core’s systems. Tails will need some time to shut it down, so Sonic and the Avatar plan to lead Neo and Infinite away from the core. In the midst of this, the Avatar is put off by Sonic’s typical over-confidence in this plan, having almost been thrown into Null Space thanks to his reckless actions. Regardless, the two travel in and out of the Death Egg, with Neo and Infinite giving chase, leading them away. Now all that’s left to do is to stall the villains long enough to give Tails the necessary time to destroy the Phantom Ruby core, thus giving them the opportunity themselves to destroy the Phantom Rubies. In this brief period of downtime, the Avatar is still irritated, which Sonic notices, realizing it as a result of his arrogance when trying to take the two villains on his own, an act that almost doomed the Avatar. Sonic admits he’s at fault, and realises his attitude and brash decision-making can put him and others in danger, reassuring the Avatar he won’t make the same mistake twice, and that he can take the lead in this fight.

The fight soon arrives, with Infinite bewildered by the Avatar’s unexplained escape from Null Space. Sonic and the Avatar race in to fight Neo and Infinite one more time, being drawn into many mind-bending illusions and constructions in Null Space, with their powers having increased thanks to the continually charging of the core. They hold out for long enough for Tails to shut down and destroy the core, leaving the two villains vulnerable. Neo and Infinite clamber over each other, hastily using their remaining power to charge into the heroes head-on and destroy them as a last-ditch effort, but that is ultimately no match for Sonic and the Avatar, as they fire back with a move so impressive and in-sync that it destroys both Phantom Rubies, ending it’s reality-altering effects for good.

As a result, all of the Phantom robot armies begin to shut down, as all traces of the Phantom Ruby’s effects begin to reverse. Including the capture of Dr Eggman in Null Space, who returns to deliver the message that he was responsible for redirecting the Avatar to the Death Egg, as they were left with the tools to manipulate Null Space from within. This gave the Resistance the knowledge of the Phantom Ruby core and thus the advantage they needed over the villains, leading to their victory. With this only being a hologram message, Eggman disappears, leaving Sonic and the Resistance return back to their world to begin the Restoration.

Back in the now closed-off Null Space, Infinite and Neo are stuck without Phantom Rubies, totally powerless and with no possible way out. Without the Ruby, Neo transforms back into his regular, non-talkative body, leaving the two to live out the rest of their days in the void.