What doesn't kill you makes you wish you were dead
Media of origin: Fallen Hero: Rebirth player character Villain name: Vendetta Villain type: Ruthless Vice: Sugar (he likes suckers) Romantic interests: M!Ortega (ex), Steel (current) Grayson originated as a character for the interactive fiction series Fallen Hero. After tens of replays of the first game as Grayson, I ended up constructing a somewhat elaborate AU for him that was very similar to the regular game, but that filled in some gaps and tweaked some things I didn't like about the story and characters. Also, while I know a few of the important reveals that take place in the second game, I haven't played it. I actually only just found out while writing this page that the second game is available to play (it was just a demo last I checked and I prefer to wait for full releases). All this to say, if there's anything here that contradicts canon, it's either part of my AU or due to my very limited knowledge of anything in the second game (I guess Steel is actually romanceable in that one???).
Personality
Grayson is a molotov cocktail of rage, resentment, insecurity, and self-hatred. He responds to every emotion with anger and mistrust. He's always had to fend for himself, and even when he's had friends or lovers he's had to keep his true identity from them. He's never really trusted anyone. Even a kind word to him is met with suspicion or outright rejection. Lucky for him, Ortega likes a challenge and is almost as stubborn as Grayson himself.
Background Spoilers ahead for Fallen Hero, although they are heavily mixed with headcanon and AU elements
Grayson is a re-gene, a creature who probably used to be human, but has been genetically enhanced in a government facility to have superpowers. He doesn't actually know if he was created in the facility or if he was a regular human once; he has no memories of any childhood before the lab, but he desperately wants to believe that he was once human.
Grayson's superpower is telepathy. He can't turn it off; whether he likes it or not, he can always hear the thoughts of everyone around him as if they were speaking aloud. This constant sensory overload makes him irritable, and on his worst days he can hardly function over the sound of every person in the city thinking all at once. It was easier when he was younger, but each time he's been returned to the facility his powers have been pushed farther and farther, enhancing his abilities far beyond what an average telepath might be able to hear or do.
A few years before he escaped and became Sidestep, the scientists considered Grayson "complete" and ready for use in the field. He was planted in the seedy underbelly of Los Diablos and used as a spy, infiltrating many of the most powerful gangs of supervillains and lackeys and passing information on their activities back to the government. Later on as Sidestep he went undercover again, his previous experience and relationships with these villains making him an invaluable asset to Ortega and the Rangers. These connections proved useful once again after his fall from grace led to Grayson becoming a villain in his own right.
A very powerful telepath, who acquired their powers through regular means, tops out at around a level 7 telepathic ability. When Grayson escaped the facility for the first time in his life, he was hovering around a level 9, the highest power rating thought possible for superpowered humans. This was when he operated as Sidestep. Helping people made him feel almost human, like he might actually be worth something. After the Heartbreak Incident, he was recaptured and further experimented on, which after many years pushed his abilities to what the scientists called level 10—higher than any telepath in history. Unintended by the scientists, this gave Grayson a new power that no telepath had ever unlocked before: the ability to "puppet" or control the minds of human beings. Grayson was able to escape once more using this new power. After almost a decade spent back in the hellish facility, he was changed, and had no desire to return to being Sidestep the plucky vigilante superhero. No matter how hard he tried, he couldn't bring himself to believe that anything could make him feel human. Seeking fulfillment in life was no longer an option. Now, his only moivation was to keep himself free of the facility long enough to become the government's worst nightmare: a vicious supervillain who would stop at nothing to take down those responsible for his long imprisonment.
After the events of Rebirth, Grayson was once again recaptured by the facility. This time, he is rescued by Ortega and Steel, but not before the scientists have pushed Grayson's powers even further past their limit to what they call level 11. Now, Grayson's ability to puppet others' bodies does not require him to be unconscious while it happens; he can freely access multiple minds at once and control their bodies, while still fully in control of his own body and mind. The scientists theorize that a level 12 is possible, but it's unknown what new power this might unlock for Grayson. He does not intend to be recaptured again to find out.
AU notes
Probably the most notable difference between Grayson's AU and canon is that his puppet, Dick, is not (usually) a comatose guy. I got attached to the idea of Dick as an actual character, and in most versions of the AU I consider Dick to just be a guy Grayson hired, like a henchman. In the OG game, Dick was obviously a name Grayson gave to the puppet as a dumb joke (canonically a dick joke but for me it was a Dick Grayson from Batman joke), but now in the AU it's more like a semi-affectionate nickname he uses for his henchman.
There's also quite a lot of semi-canon that I've extrapolated and messed with regarding the Sidestep backstory and the re-gene origin story. At this point, I don't remember what's canon and what's AU when it comes to that stuff.
Romances
Grayson and Ortega dated back when Grayson was Sidestep, but they were always a hot mess. They had strong feelings for each other, but they argued constantly and broke up multiple times over stupid disagreements. Grayson never got along well with Steel, either, but while they didn't like each other, they'd always have each other's backs when it mattered. In the present day, while Ortega tries to rekindle their old relationship, Grayson can't seem to muster the same hotheaded passion he used to feel for Ortega. Instead, he finds a surprising comfort in Steel's stern stoicism. Ortega still sees Grayson as Sidestep, the firey kid he used to be. Steel recognizes that Grayson isn't Sidestep anymore, and maybe never was. He always saw beyond the mask more clearly than Ortega could. Maybe that's why now, Grayson finds himself gravitating towards Steel's company, even though he knows that that very insight could reveal him for who he really is. Even a villain can't help but crave to be known.