Well, obviously Deku in two forms - the younger and the older version are the main characters. The younger Deku is the one who is still growing and learning, while the older Deku has more experience.
Villain Deku might start to question his villainous ways. Meeting Hero Deku could make him see the good in heroism. Hero Deku, on the other hand, could become more empathetic towards those who turn to villainy. He might realize that there are reasons behind it and not all villains are just 'evil' for the sake of it.
Some characters might try to understand Deku's motives. Kirishima, who was close to Bakugou, would be angry at first but might also try to find out if there were any extenuating circumstances. However, many would be afraid of Deku, seeing him as a threat now that he has killed one of their own.
Obviously, Deku is one of the main characters. Since it's a Saiyan Deku fanfiction, he is the one with Saiyan powers. Other characters from My Hero Academia like All Might or Bakugo can also be important characters in the story, as they interact with Deku in different ways because of his new Saiyan abilities.
In the 'deku texting story', Deku is the central figure. However, considering his world in My Hero Academia, other characters who could play major roles in the texting story are numerous. His friends from Class 1 - A would be prime candidates. They are constantly interacting with Deku in the original series, so it makes sense for them to be in the texting story. Additionally, any heroes or sidekicks that Deku looks up to or works with might also be main characters. Their wisdom and experience could be shared through texting, and they could offer guidance to Deku during his journey to become a great hero.
Uraraka would be heartbroken. She was one of Deku's closest friends. She might lose some of her usual cheerfulness and become more focused on finding out who or what was responsible for his death. She could also struggle with her own self - confidence in using her quirk, as Deku was always an inspiration to her.
Obviously, Deku would be the main character since it's about being reborn as him. But other characters like All Might are also likely to be important. All Might was a huge influence on Deku in the original story, and in the fanfiction, he could still play a crucial role in mentoring the reborn Deku.
It's Deku and Todoroki. Deku is known for his never - give - up attitude and his ability to inspire others. Todoroki is recognized for his cool and sometimes aloof exterior but deep - down caring nature. In the fanfiction about their marriage, these traits interact and influence how they communicate, support each other, and face challenges as a couple.
The main characters are deku and momo. Deku is known for his tenacity and growth as a hero. Momo is intelligent and has a unique quirk that allows her to create various objects.