Slyde is an illusionist by trade, but doesn't like to perform his tricks on stage. He much prefers to demonstrate his abilities on other ponies, even if it's just to confound them by relating a new and contradictory account from his past. He feels very guilty if his jokes hurt another pony's feelings, and will do his best to make it up to them. While his stage magic is powerful, he's interested in all magic. His favorite hobby is studying wish magic, and his dream is to one day grant a wish.
He's an easygoing pony, more likely to kick back on a bench and drink hay shakes than build monuments to his glory. Because of his talents and knowledge of esoteric magic theory, a conversation with Slyde often leaves a pony wondering what the heck he's talking about. Don't give him too much credit though. Often he makes it up as he goes, especially if whatever fabrication he spins leads to a laugh. Call his bluff and he'll beat a hasty retreat. And if he ever offers to sell you snake oil... don't take the offer. Threaten to call for, he's terrified of her.
He makes a point to tell a different story every time he's asked, so Slyde's origins aren't clear. He lives in a house nearand seems to have a thing for her. Due to a flair for teleportation magic, he seems to appear anywhere, often accompanied by a ridiculous flourish such as confetti, ribbons, or rubber chickens. Town square, the depths of the Everfree, caves on the moon, even your bathroom isn't safe from an unexpected visit.
Some say his cutie mark isn't consistent. Others claim he was once a pegasus. There are scattered accounts he's changed form on occasion. When confronted with these accounts, he chuckles and says, "illusions".
His only response when asked about his magic was, "Ha! What can't I cast?" Hubris aside, he's especially gifted with three types of magic. He also has demonstrated the ability to learn new spells by watching another unicorn perform them, though this doesn't always work.
His cutie mark is a window, indicating he has insight into things that have been, things that are, and things that will be. Upon request, and with ample payment, he can peer into a pony's future and offer advice. However, the rules of prophecy in Equestria are very strict, and he might be obligated to give his answer in the form of a riddle. No refunds.
Windows are lenses and can distort our view. As such, he is skilled in spells that cause ponies to see that which isn't. His most powerful illusion spell allows him to create a convincing recreation of an area as if he'd teleported a pony somewhere else. These illusions have a short range and he must have line of sight with anypony who sees it.
Windows are also doorways. Teleportation is not a rare unicorn gift, but Slyde seems to believe it is. He rarely teleports without a flourish such as confetti, a fanfare, or fountains of cake frosting. He'll often disappear as quickly as he appears, especially if it leaves the witness confused.
OOC Notes and Spoilers
Are you crazy? It's a VERY dangerous thing to do exactly what you want. Because you cannot know yourself, or what you'd really do, with all your power.
Slyde is an experiment in self-aware RP. That is to say he knows he's a character in an imaginary world. Through this awareness, he has great power over reality. You could say his greatest spell is the ability to convince the rest of the RP he's just a pony. This aspect of Slyde stretches many people's comfort zone and will only appear if, in character, he is directly confronted about it. For example, a powerful being like Queen Titania might call his bluff.
His terror of Pinkie Pie stems from her own fourth wall powers. He knows well he shouldn't show off lest other ponies unfollow. Pinkie Pie is unfettered by "the rules" and he's certain she'll blow his cover.
Because he's more a manifestation of a player than a pony, he enjoys metajokes and has knowledge of other universes. He enjoys visiting other non-traditional ponies like. He has in his possession many magical artifacts from other worlds, many benign or used up. His most treasured possession is a Wand of Wishing he found while adventuring. Its charges are completely empty, but he considers it his luck totem.
There's a reason he is fascinated by wish magic. He doesn't like to talk about it. He visibly cringes when ponies make a wish within earshot, as if it causes him pain.
He's involved with a long-term project in the Everfree forest. It is unclear if he is a willing participant.