Matt Engarde is an antagonist of Ace Attorney.
Two years prior to his trial, Engarde dated his manager Celeste Inpax. Adrian Andrews, who would later became Engarde's manager, described them as being happy, yet he later broke up with Inpax for an indiscernible reason. Later, he learned that his rival Juan Corrida was planning to marry her; knowing that it would hurt Corrida deeply, Engarde informed to his fierce rival that he had dated her first, causing Corrida to call off the marriage; heartbroken again, Celeste Inpax hung herself, allegedly leaving a suicide note that was hidden by the man who found her body, Juan Corrida.
For the remaining years, the two men continued their rivalry, with Engarde rising to the top of his acting career. Engarde gained a reputation for being "refreshing like a spring breeze", besting Corrida in popularity polls. This culminated in Engarde's starring role in The Nickel Samurai, which competed with Corrida's show, The Jammin' Ninja. Corrida, however, conspired with Andrews, who became Engarde's manager, to disclose the suicide note, which Corrida had actually forged, that would destroy Matt's image.
During the Hero of Heroes Grand Prix at the Gatewater Imperial Hotel, which the Nickel Samurai won, Corrida arranged a press conference, during which he would appear in the Nickel Samurai costume and reveal the false suicide note. Realizing that Corrida was a threat to his reputation, Engarde purchased spy cameras to keep close tabs on him and eventually hired a professional assassin named Shelly de Killer to kill him for the bear figurine that contained Inpax's suicide note. Not trusting anyone, however, Engarde secretly recorded the killing to use as a way to blackmail de Killer should he turn on him. De Killer posed as Engarde's butler and as a bellboy at the hotel where Corrida was murdered to ward off suspicion.
Despite Engarde's plan, Adrian Andrews unknowingly incriminated him as the murderer by taking de Killer's trademark calling card from the scene of the crime, which would have made it obvious that Corrida was assassinated. After being arrested, Engarde ensured that he got the great defense attorney Phoenix Wright defend him by ordering de Killer to kidnap his beloved assistant, Maya Fey, and remotely offer a deal for the lawyer: Engarde's innocence for Maya's life.
During the trial, Matt was rather uncooperative and unhelpful towards Phoenix, knowing that de Killer would make sure Phoenix won the trial. He acted like a soppy actor for the largest part of the case in order to make sure Phoenix would continue to defend him. When Phoenix eventually learned of the truth, however, Engarde revealed his truly sociopathic nature, and openly mocked Wright: Even though he now knew his client was guilty, he would have to get him declared innocent anyway, or else his best friend would be murdered. Now knowing for certain that his client was actually guilty, Phoenix became very indecisive on whether to save Maya's life by defending Engarde, or prevent Adrian Andrews from being wrongly arrested by bringing Engarde to justice. Ultimately, Engarde's admission to his acts had caused him to be seen as so horrible, everyone in Phoenix's general orbit—Maya's cousin, Pearl Fey, his late mentor, Mia Fey (being channeled through Pearl), Detective Dick Gumshoe, and even Phoenix's two main rivals, Miles Edgeworth and Franziska Von Karma—was brought together to work with him to find a way to foil the sociopath and bring him down for good.
In the end, through the cooperation of every aforementioned party, Wright achieved a miracle: He got Matt Engarde declared innocent, but also managed to reveal to Shelly de Killer via radio that Engarde had planned to betray the trustworthy and honorable assassin all along, using footage of him killing Corrida to blackmail him. Enraged, de Killer informed the court that he valued trust in his line of work above all else, and that when any of his clients betrayed him, he hunted them down as his next target no matter how long it took. Terrified for his life, Engarde desperately begged the judge to overturn his verdict, feeling that prison was the only place he would be safe from de Killer's wrath.
Though it is somewhat the same, Matt has two various breakdowns after he was threatened by De Killer and was about to meet his verdict. Player is asked by the Judge to choose the verdict for Engarde himself. If Matt is called not guilty, then he gets scared for his own life and scratches his own face violently several times while frantically screaming that he is "guilty". When he finally stops, his face is covered in wounds and his hands are dripping with his own blood.
In case Engarde is called guilty by Phoenix Wright, he becomes shocked with the verdict of his lawyer spoiling his image, who explains to him that either way, Engarde wouldn't be able to hide from his crime—either he could go to prison or meet his end by the hands of Shelly de Killer. Matt violently scratches his own face, being desparate and mad about his verdict, even though he knows that it truly is the only way to keep himself safe and alive.