Johnny is dynamic character for many reasons.
The reason why Johnny is a dynamic character, first because he killed someone (a soc).And because of that he lost his innocents. But at the same time he was just trying to defend himself and Ponyboy.
The socs were drowning Ponyboy. Johnny was just standing scared, and not knowing what to do. So Johnny stabbed the soc and killed him. Second because after Johnny and Ponyboy left the city Johnny rescued the children in the burning church, and risked his life doing it.
Johnny’s motives are good. Because again he saved the children in the burning church. And even though Johnny killed the soc he still managed to save his friend (Ponyboy) from being drowned.
Johnny is not like any other Greaser. One because he is a hero. And any other Greasers would have let the children burn to death in the flaming church. But Johnny didn’t, he went inside the church, rescued the children, then died after saving them. Two because he was scared of his own shadow. Other Greasers are not scared and they are rough and tough. And three because he changed people’s thoughts about the Greasers when he saved the children.
Johnny was looked at like a hero because of what he did. Again because he was looked at like a hero because of saving the children and risking his life, and died.
But someone said “stay gold”.
Again any other Greaser would have just let him die. Also the including the socs. He was looked at like a hero because of saving the children and risking his life, that making him a dynamic character.
That is why Johnny is a dynamic character, and a hero.