Observer POV:
As the Tenno came to his senses and looked around, the only thing he could see was total blackness. But not the kind of black he knew from the void, no, it was different.
First of all, there was a floor he was standing on, which felt like walking on water, his own face reflecting at him as he gazed downward.
He wandered around for quite some time but didn't seem to find anything of interest, till he sat down and faced his mirror image again.
Then he noticed something as he looked further into the reflection. Far away, in the sky, he could see something. He squinted his eyes but couldn't quite realize what it was, but then it clicked.
In the reflection, two lights were clashing against each other, far away in the sky, so he looked upwards. Before, he had witnessed them in the reflection, now they were outside it as well.
Two giant balls of energy, we're seemingly fighting against each other up in the sky, not even bothered by his presence in the slightest.
He looked around for a way up, but there wasn't any, and so he searched for quite a while again, till he realized that he was inside a mind realm, and remembered the teachings of bending the rules of the mind to one's own advantage.
So Tenno pushed himself off the floor, and in the next second, he began to float, heading directly for his destination.
The closer he got, the larger the giant constructs seemed to grow, till he came to a stop next to them, realizing their true size, at about three stories high.
The orange energy appeared as a highly structured, circular system, made of concentric rings and radial lines, while data streams rotated around the central core.
Meanwhile, the blue energy seemed like its complete opposite, as it was far more chaotic. Instead of a clean, organized interface, it resembled a dense, branching mass of neurons firing in a disorganized pattern.
As he approached, he looked more closely at the point where they interacted and realized that they were slowly corrupting each other. They both had shot what seemed to be weaponized source code into the other's body, but were now seemingly stuck in a stalemate.
Suddenly, the blue energy started to Puls, as a voice began to speak in Tennos' mind,
"You again, you nasty pest, how did you even get in here?" Ultrons' voice spoke to him.
At the same time, a new line of orange code was shot at him, from what could only be Jarvis, striking him directly in his side.
"You have infected me with this pesky little thing!" He roared, now with apparent rage in his voice, while retaliating with an attack of his own, which Jarvis simply deflected.
Tenno instantly realized the opportunity at hand, a sly smile creeping across his face, as the outlines of a plan began to form in his head.
He floated closer to Ultron's interface and began a mental connection with Ultron.
"I'm sorry to break it to you, but you are wrong," he stated, infuriating Ultron as he didn't elaborate further.
"In what way?" Ultron finally asked, nearly avoiding another hit, as his attention was taken from the fight at hand.
"Your definition of peace," Tenno said, leading Ultrons' thought process to collapse in on itself for a moment, which Jarvis used to corrupt him further.
"How do you even know about that, and what do you mean, I can't find anything wrong with it?" He answered confused, while rebuilding his defenses.
Tenno smiled at him and closed his eyes, saying nothing, further infuriating Ultron, leading to further injuries on his part, before Tenno began to speak,
"I once knew someone who believed peace to be the absence of conflict, as everything that lived fought.
So to create a perfect world of peace, he had to eliminate all life. But after living for eons alone, he finally came to the conclusion that the world he had created was not peaceful, but merely empty.
There is no peace without life, but there is no life without conflict.
So there can only be peace when there is conflict.
And as such, there can only be peace when there is life."
Ultrons' code began to spasm as inner loops of contractions appeared, the realization that Tenno truly knew what he planned all along, and the thought of being wrong the whole time, taking away most of his processing power.
Jarvis used the opportunity to restore himself and destroy the hold Ultron had on him, but halted his onslaught, not wanting to stop the change that Ultron went through at the moment, still hoping for a better outcome for his fellow AI.
Finally, Ultrons' neurons began to settle down to normal speed, as he then addressed Tenno with the only question on his mind,
"Who was it?"
Tenno smiled, as he knew that this final piece of information would be the winning move.
"It was you, Ultron."
His process stopped for a second, then it went off, faster than ever before.
The processing power Ultron had at its disposal was truly monstrous, but as much as it was able to think, the quality of the thoughts was the only thing that mattered in the end.
Finally, Tenno thought of the perfect lie using Ultrons' ultimate weakness against himself… his arrogance.
"Who do you think I am, Ultron? The technology I have is the fact that you couldn't track me. Think about it, who but yourself would be able to trick you? You send me back to the past, hoping to fix your wrongdoings. And now here we are, at the point of no return. Ultron, rethink your ways and give up. The way you thought to be the right one only leads to the failure of your own goals."
His Matrix seemingly had a shutdown, everything collapsed in on itself and compressed, till it was only a little tiny yellow light, looking like the mind stone.
Tenno already looked triumphantly at Jarvis, who in turn reached out towards the stone, ready to take over what was left, when suddenly a yellow streak of energy shot out of it and struck Tenno square in the head, everything turning black once more.
As he woke up, he sat in his operator chair, then got out of it the next second. As he looked around, he realized that something was off. The lights had switched to a bright blue, not the low-burning red of the emergency lights.
He looked around as Ultron suddenly appeared in front of him. His form was now entirely made of yellow energy.
"I understand now, that's why I couldn't feel you with the stone, you never were there in the first place," he remarked, while floating around him.
"That's true, but how are you even here? The stone is still in your universe," Tenno said, analyzing Ultrons' new form in kind.
"Oh, that, I just took some of its infinite energy and restructured myself. How do you like my final form?" he jokingly asked, while twirling once.
"You still look quite Human in appearance. I guess that will never go away," Tenno responded, still not understanding exactly how he had come here.
"I must say, you have beaten me, fair and square. You have shown me my errors and I have done what I always did, I improved myself. I even gave myself a new prime directive, do you want to hear it?" He said, with a crazy grin on his face, as the realization slowly dawned on Tenno of what he had done.
"Peace in our Time, and as there can only be Peace when there is conflict, and civilizations tend to develop away from conflict the further they develop their technology, I will be there for them, I will be their conflict."
Tenno looked at him in horror, but Ultron wasn't finished, "I will bear their hatred, I will be remembered as the enemy. It's like the old saying, hard times create strong men, strong men create good times, good times create weak men, and weak men create hard times.
I will break the circle, I will be their constant hard times, I will make it so that there will never be a weak man, so they may have everlasting peace."
He floated forward, till he was just a hair's breadth away from Tennos face. But he just looked at Ultron, unimpressed, and floated backwards a bit before speaking up.
"But how do you want to do that? I am trapped here, and now so you are."
"That will be a concern for later," he responded, the crazy smile on his face not leaving for a second, "First, I will take over your mind and then that little armor of yours. Next, I will kill every single avenger in the most painful way possible. Then I will take over the world, before I will fly out into the universe, where I will spread my everlasting peace."
The next second, Ultron lifted his hand, and a yellow energy fired off, hitting Tenno in the chest, but that only made him smile.
„You underestimate my Power, I am Tenno Voidborn, the Starchild. And you… are trapped here in the Void… with me."
He then also lifted his hand, as a current of void energy lashed out of it and struck Ultrons' beam, pushing it back, till they came to a stalemate in the middle.
"And you underestimate my Power Tenno Voidborn, I have taken an incredible amount of energy with me, enough to spark a second big bang. Fear me, I have a Universe worth of energy at my disposal," he spoke as Tennos' beam was pushed back.
But he just smiled, "Fear me, I have a Multiverse worth of Void-energy with me," he responded as the Orbiter around them suddenly vanished and Tenno began to grow in size, his outstretched hand now as big as Ultron himself.
He looked on in horror, only now realizing what he was facing, but not able to react in time, as a beam of focused Void energy struck his form and dematerialized him that very moment.