Warning! Spoilers ahead for My Hero Academia chapter 338!
Some fans recently came up with an intriguing dark theory about why Deku wants to forgive Yuga Aoyama in My Hero Academia, but the only reason why they came to this shocking conclusion is because of Katsuki Bakugo's own personal shortcomings, which he later put on full display for his classmates to condemn.
My Hero Academia's traitor arc has undoubtedly meant to further underscore Deku's true heroism, for this isn't the first time he's forgiven criminal behavior. The most recent example occurred when he convinced Lady Nagant to rejoin hero society and face the consequences for her past crimes even though she was literally hunting him for All For One. But when Deku later emphatically makes the case for hero society to give Yuga another chance, Bakugo taints Deku's good deed by creating the false impression that his classmate must have ulterior motives when he thinks, "Deku! I get it now!!" in chapter 337.
But as Bakugo is ostensibly incapable of realizing, there's nothing else to get besides the obvious. My Hero Academia later proves that Bakugo's belief that Deku can't possibly be willing to help Yuga out of the goodness of his heart is just the product of his own failings when Bakugo becomes the only student of class 1-A who's incapable of forgiving Yuga for his betrayal. Deku doesn't just want to excuse Yuga for his crimes so hero society can use him against All For One. Deku wants Yuga to prove himself worthy of being forgiven because, as Deku asks, why should someone be labeled a villain for just making one mistake?
Although Bakugo has made some incredible strides since his introduction as being nothing more than a bully, he still has a long way to go before he's a decent human being like his classmates. And the fact that he believes that there must be an angle for being kind is proof of that. But more importantly, this misunderstanding demonstrates that he doesn't actually know Deku. Bakugo has witnessed Deku perform some incredible deeds and yet, he still believes that Deku is capable of using someone so abominably.
No, the traitor arc isn't meant to uncover a dark side to Deku. In fact, My Hero Academia had the chance to taint Deku's character during his solo mission to take down All For One alone. Deku had been undergoing a dark transformation that was obviously consuming him during that time, but immediately afterward, My Hero Academia made it abundantly clear that the entire experience was for naught because class 1-A was able to save Deku from this darkness. Although Deku having a more sinister reason for saving Yuga would have been a logical progression, all of the darkness that had consumed him during his rogue mission immediately evaporated. Bakugo's flaws prove that Deku's portrayed in My Hero Academia make this development completely random and unwarranted.