The black suit he wore during his time in Canterlot was a symbol of the place. A symbol of his control and riches, yes, but also of Canterlot conformity dancing in the guise of excellence. But with the enchantments he placed upon it, letting the cloth grow to coat him in a magic-enhancing cloth armour suit at a moment’s notice, it became his symbol of small, hidden rebellion. It went from a simple Suit to a Power Suit. With its ability to drain and negate any magic he didn’t approve of, the black suit he wore granted him protection from magic in a highly magical city, and the seemingly-ordinary metal of his horseshoes granted him the power to move mountains. He couldn’t figure out a way to reliably harden it without hurting its flexibility, however, so he didn’t bother with that.
 
But after moving to Ponyville, he felt a change of wardrobe was in order. It didn’t exactly help him blend in. When his Silver Spares had finished their upgrades on his Power Suit, he had them change its colours and infuse it with the few elements of his experimental “Final Suit” they’d finished their ground-breaking work on. Genetically-altered and “Domesticated” versions of some of the most powerful symbiotic life forms in the universe were, in one of his labs, finding themselves altered to serve as the building blocks for the greatest suit in the multiverse. However, work on this was slow, and documentation on the subjects in question was hard to find, even for one with his connections. Many life forms seemed impossible to crack the code of. Only the stable and finalized samples of the thousands of life forms his Spares were working on found themselves added into this suit: The lab-grown genetically-enhanced magically-empowered daughter of an emotion-eating white-eyed black slime monster of unknown origin and a psychic somewhat-acidic plant-controlling plant-matter-drinking pink slime creature of equally unknown origin, a blob of black and white slime with green markings and the abilities to reshape itself, possess technology, and enhance technology, a once-extinct green unicellular creature with the ability to remember what it “Ate” (Licked) and partially or fully manifest traits of devoured DNA for self-defense, living plasma (And not the kind you’d expect!) from a space-faring race of physically-stable living flame creatures, cells from an angry little blob of pink bubblegum-like… something that took far too long to gene-edit before its inherent evil and chaotic nature could be purged from it, semi-real fur from a sentient mass of pure data able to self-modify its own programming and learn from the data it obtained during its life, and some kind of living fibre he’d bought from a multiversal dealer of ill repute. Genetic manipulation on this scale would require an unrealistic level of magical power, or a decent laboratory with stolen equipment and a lot of time. And to combine these life forms would be impossible for science, but not for magic.
 
Silver designed the recipe for this thing, so he expected its many abilities to interact with and enhance one another, while negating any downsides he hadn’t already edited out of the sample creatures. For example, its “Control and enhance” technology ability can now extend to living beings, its ability to manipulate its acidity to break down pretty much anything evolved the additional ability to manipulate and excrete its own chemical compounds, and its ability to learn and mimic genetic data became the ability to learn and mimic any data. Electricity and extreme heat cannot hurt living flames able to feed off any element. With multiple avenues to feed itself and “Heritage” from a few beings that had no need to eat, it has no need to mess with the emotions of its host and feed off its wearer’s excess feelings. Best of all, loud noises make it stronger. The first time it hears those specific noises, that is. Then the noise becomes information it already knows, and can’t grow from further. Even giving it misinformation won’t hurt it, which was the only weakness of the data being he’d sampled.
 
As he fed it books and enchanted items to absorb the data, knowledge, and magic of, he expected it to develop some sort of sentience, and he’d prepared for this occasion, as the books on morality and the benefits of being good lying nearby during her first feeding session could verify. He even had a name ready for it. A name that went unused when this being chose to name herself “Suit”. And he didn’t expect her to become anywhere near as intelligent as she is, and with how simple she acts, others likely wouldn’t expect her to be smarter than Silver either. She’s rather well-behaved, for a sentient suit of living slime, and she sees herself as Silver’s firstborn and favourite daughter. Suit misbehaves infrequently, and usually only does this to obtain DNA samples from powerful life forms without her host’s permission. She misbehaved a lot in the first chapter she appears in, but those were attempts to help him. Like when she started tickling him in the middle of a funeral Fluttershy was giving to one of her Hamsters. He got her to stop at the chapter’s end.
 
In this suit’s Initial Stage, the one you can see in the image, she appears to be an ordinary blue suit with a golden tie, an orange undershirt, golden cuffs, and orange eye patterns here and there. Eye patterns that are really more decorative than anything, considering her ability to see out of herself. Eye patterns that can express what the suit is feeling visually and move around to focus on you, if you catch its attention. It even feels like ordinary cloth, albeit cloth that can reshape its physical texture, size, length, and current colour at will, a testament to this slime-creature’s ability to mimic the textures of different materials. However, this is still a blob of living slime in the form of a suit, enhancing its wearer and able to protect him from pretty much anything. Slime arms can emerge from it and shift into anything at will, with or without Silver’s consent. In the suit’s Second Stage, the cloth texture is dropped in favour of its true slime texture, and it engulfs the host fully, keeping him alive and protecting him from pretty much anything. Suit says she has a Third Stage, something Silver didn’t give her when designing her, and he’s not inclined to find out what that Third Stage might be outside of an unforseen and extreme emergency some time in the future.  
The suit is made of living data that typically mimics the texture of goo, when not in its “Ordinary cloth suit” disguise. Oh, how symbolic it is to clothe oneself in information itself!
 
Also, this really is my new Derpibooru account: https://derpibooru.org/profiles/SilverStarApple7