Chapter Text
Metal Sonic did not feel physical sensations in the way that living beings did.
Instead of actual tactile sensation, he was fed environmental data by his sensors- cold and calculated numbers that told him how many Newtons of force were being exerted against his artificial form, what the temperatures of the air and the substances he was in contact with were, how many regular or irregular alterations in elevation and smoothness were present upon a surface, and so on. He was given the hard data for what he was touching, and from there his processors extrapolated and approximated what he would be feeling if he was alive, providing the phantom feelings of pressure and heat and texture. And even then, these phantom sensations weren't even all that accurate, for his original data model contained organic memories of what the sense of touch actually felt like, and... his artificial body, his sensors and his processors, fell quite a ways short of the mark.
He could not feel the pressure of the fists and feet and quills that struck and sliced and dented his casing and chassis time and time again.
He could not feel the soft and misty and nearly insubstantial texture of the clouds as he soared through them, on his way home.
He could not feel the warmth of the hands that pieced him back together when he finally made it, back to the man who had created him.
Perhaps it was a good thing that he didn't have an organic sense of touch. With all of the fights he entered and all of the failures he subsequently experienced, his existence would undoubtedly be plagued by the pain of the damages he sustained, itching and burning and distracting him from completing his objectives. Yes, perhaps it was better that he couldn't feel the world around him as a living being would... but he still couldn't help but want to.
The robot, built and programmed in the image and identity of Sonic the Hedgehog, possessed actual memories of what it was like to be alive. He remembered what it was like to feel the warmth of the sun upon his skin, he remembered what it was like to feel the wind rushing through his fur as he ran over the hills, he remembered what it was like to feel the earth beneath his feet. This organic life, this living and breathing state of being- he remembered it, and he wanted it, because the manner in which he felt things now was so cold and impersonal and unhappy in comparison.
At least, with the sheer depth of his desire for these physical sensations, he knew that he could feel emotions as strongly as organic lifeforms could.
Eventually, Metal Sonic set aside these desires, focusing upon the goals that his creator had given him. In the back of his memory, however, the sensations lingered, and his processors attempted to replicate them in the formation of phantom feelings that brushed through his awareness as lightly and delicately as a butterfly upon a flower petal. He set aside his want for the real deal, but he never forgot it, always falling short of what he wanted. It lingered, teasing him as something that he could not have, but then... then he was given the opportunity to obtain it.
Nanites. The nanites being used to create the semi-organic first-generation model of Shadow Androids intended to actively serve the Doctor, those tiny machines that possessed such incredible versatility, that were not intended for him but some of which he ended up taking for himself in the pursuit of his primary objective anyways. It took some of his attention away from his goals, slowing him down in a way that would have infuriated him under any other circumstances, but he was chasing after something he wanted. He didn't care that it took him a few extra days to properly seize control of the Eggman Empire and prepare the stages for his show, not when he was creating something so incredible with his own two hands... and not when he finally succeeded.
The emotion that surged through his processors as he felt the hot asphalt of the airship deck beneath him for the first time could only be named as euphoria, for he had succeeded. It was such a small success, such an insignificant thing in comparison to the many failures that overshadowed his existence, but he could finally feel again. Even as the hot asphalt stung his artificial fingers and palms, at the moment physically softened in order for his new semi-organic/organic-mimicking sensors to function properly, he was filled with joy and satisfaction. Laughter bubbled up within his systems, escaping his speakers and creating such a light and delighted sound that it could have easily inspired a similar joy in others, should anyone else have been present to hear it.
He could feel again, and it was just as wonderful as he remembered it being. Perhaps even moreso, considering how long he had existed without such sensations, causing his sensitivity to them to heighten in their absence. The rough asphalt beneath his hands burned, but he still couldn't get enough of it, laughing and even giggling like a child, with another piece of himself falling into place. This felt right to him, it felt so good to be able to feel again, and he truly believed that he would never grow tired of these sensations.
This was another piece of what it felt like to be alive, that state of existence that he had felt so separated from ever since he had powered on for the first time, and perhaps someday he would be able to fully experience that state again despite this artificial body of his.
The feeling of euphoria from this success remained with him for some time afterwards, inspiring him to go beyond a simple invitation letter for Sonic to come and stop 'Doctor Eggman' from taking over the world. He was, in fact, quite giddy as he sacrificed some of his nanites for the letter, allowing it to play audio and video instead of remaining cold and silent with mere letters upon an unresponsive surface. There was no purpose to this action, no purpose to making this letter one of the most innovative pieces of technology in existence when compared to the level of technology attained by humanity in general, save for the expression of the joy inside him. He knew that it was ultimately meaningless, that nobody outside of himself would know or care about it, but it made him happy.
He was happy as he sent off the letter, happy as he impersonated Sonic to collect a Chao and the frog that had been in contact with Chaos while he was deactivated, happy as he took on his creator's form and began the process of impersonating him. The soft gloves upon his disguised hands, the brisk chill of the brightly-lit nighttime, the sting of loose wires sparking as he was 'defeated' by both those invited and those who showed up as a surprise... He was living for them, no matter how artificial his body may be, and nothing could make him regret giving himself the capability to feel physical sensation again.
Nothing could make him regret this upgrade to his existence, even as he tasted failure again for it, even as he lost it once more by being forced back into his original form. As long as he retained his memory of the process, as long as he retained access to his upgraded form, then his failure here wouldn't matter so much. What was one more drop of uncertainty in the bucket, after all, compared to a full glass of joy? What was one more splash of despair, compared to a river of satisfaction that would continue to flow onwards? Even as he powered down in the grasp of an enemy, he did not regret the distraction that his organic senses had provided him, for obtaining them once more had been a step towards the state of existence he wanted to be in...
He was one step closer to becoming the Sonic that he could remember being, thanks to these organic senses of his, and someday he would return to being the carefree hedgehog he could remember being so very long ago.