MOTHER'S SUICIDE — Although his early childhood with his single mother was far from ideal, between the financial difficulty of a single-parent household and the stigma against single mothers in Japan, Akechi's status as an unwanted child didn't really start to sink in for him until his mother killed herself, disrupting his kind bubble of childhood naivete. Even as a child, he knew it was his absent father's fault; that if he hadn't abandoned them, his mother wouldn't have been so miserable she committed suicide. This is when his bitterness took root, and he became lonely, traumatised by his situation as much as the loss he experienced. He wasn't just an orphan; to his understanding as a child in that tragedy, he was a boy orphaned because both of his parents decided they didn't want him, one of them having abandoned him before he was even born, and the other having loved him so little she would rather die than look after him. It defined everything for him, for the rest of his life.
ORPHANAGE EXPERIENCES — Akechi describes his time as an orphan poorly, saying that he was passed back and forth between the orphanage and various foster families, never staying with one for long. It isn't so much a single event as a number of smaller incidents that established a pattern: if Akechi wasn't what people wanted from him, then he would be abandoned again and again, just like he was by both of his parents. Whether it was something wrong with him entirely, or something to do with the way the world worked, he was fundamentally unwanted and unlovable. So, he learned to manipulate people, to wear masks, to craft an identity specifically designed to make people love him so that he wouldn't be cast aside — which is exactly what he does later when he becomes the "Detective Prince." And they were lessons he learned fast, trying to beat the timer over his head that counts down to the age at which an orphan is no longer considered adoptable, but in the end, there was never a family he stayed with, and he continued to be alone.
CHOSEN BY YALDABAOTH — At around 14 or 15, the "god" Yaldabaoth chose Akechi as one of two capable vessels, and bestowed upon him the power of Persona and the Wild Card. What this really gave Akechi was the opportunity for revenge. He'd already become jaded and resentful of the world, which had given him nothing but misery after misery, and he finally had a trump card that allowed him to be more than a pitiful unwanted child. With the power to enter the Metaverse, he was set on the path of playing the long game to plot out his father's downfall no matter the cost. This resulted in him becoming a teenage assassin to earn the man's trust, constantly walking a knife's edge whereby his life and death were separated by how "useful" he could be, and the detached, manipulative nature that had been fostered by his childhood experiences sharpened into something worse — he became ruthless for the sake of his goal, willing to kill on command, to twist people into mindless monsters so that he could use them as stepping stone "crimes" for the sake of his detective image. It was obsession that consumed him; literally everything he did from then on was done in waiting for revenge, the only thing he wanted, an end point that he didn't even need to live beyond as long as he got that satisfaction.
MEETING THE PHANTOM THIEVES — While it doesn't seem to have much of an impact on him at the time, in retrospect, Akechi acknowledges that they had an effect on him, Joker more so than anyone. He was jealous of them for their friendship, and the ease with which they disregarded a society he had spent so long desperately trying to appease; he envied Joker's natural charisma and how comfortable he was with being an outcast, how he could be loved even with his damning reputation, and meanwhile despite his carefully constructed personality, Akechi remained unwanted and unloved with a crowd of adoring fans who would turn on him in an instant if he made the smallest mistake. He doesn't deny it when Morgana later says he took a liking to Joker, and says himself that he wishes they could have met a few years earlier, before he went down his irredeemable path of revenge. He was affected by the Thieves; it just wasn't enough to change his mind when he was so close to having vengeance.
DEATH — ... But it was enough to change his mind the second time around. When the Phantom Thieves beat him for the final time in Shido's Palace, Akechi expected them to kill him, even telling them that they ought to "get rid of [him]" if they didn't want him getting in their way again; he was plainly shocked and unsettled when they not only refused, but also invited him to join them in taking down Shido once and for all. Akechi has always lived by the belief that if he is unwanted or useless, he'll be discarded, first as a child and later as a threat on his life from Shido; at his lowest point, the Thieves, who should hate him more than anyone, still consider him worthwhile. It shakes him. And upon seeing Shido's cognitive version of "Goro Akechi," he realises that his plan was a failure from the very beginning, anyway. He learns that Shido had manipulated him with both praise and threats, and he had fallen for it like a stupid child because he was so desperate for approval and recognition — and so, at the end of the line, Akechi decides to sacrifice his own life to give the Thieves a chance to finish what he couldn't.
» FIT:
Despite his age, a decent fit! Akechi developed his independence very young, as many children in orphanages do, internalising a need to prioritise himself and his own survival over anything else; and then in his early teenage years, he became an assassin working independently for Shido, which meant his life was on the line every minute, and that's putting aside the things he had to do in the Metaverse. He's adaptable and unflinching, largely because he had to be for his revenge to pan out, so while he may sometimes be shaken, he won't cower from the horror aspects of the game. He's also a detective, even if an amateur one, which means he'll work well with exploration and mystery elements.
» POWERS:
Akechi is a Wild Card Persona-user, which means he can hypothetically contain multitudes of different Personas, the same way Joker can, as long as he has a means by which he can acquire them — and, presumably, as long as he builds Social Links to strengthen those of other Arcana, which may explain why his only two Personas are both of his own Arcana, Justice. His two that appear in-game are Robin Hood and Loki.