How to make lightning scars long lasting or permanent?
So one of the characters in my story gets defeated by getting struck by lightning, normal lightning. Specifically, the main character gets lightning attracted to his sword before throwing it at this character, who then grabs his sword only for it to get targeted by lighting and they get contact-struck by the lightning. However, this character continues to be prominent even after this and I want them to have the lighting lichtenberg figure scars for a long time or even permanently, and maybe some kind of disability that they have to work around for the rest of the story.
The problem is, from the research I did lichtenberg figure scars typically go away in a couple days and I want it lasting longer than that. Already part of the reason I can come up with for why they might last longer on this character is because they didn’t receive medical treatment until a long while after the strike and likely didn’t receive very much burn treatment even for days afterward, but I don’t know if that would actually be enough to make the scars permanent or longer lasting.
This is a low fantasy as well, so magic lightning or other things like that don’t exist in this world
So I guess my question is this: is not receiving burn treatment soon after a lightning strike enough of a reason for the scars to be long lasting, and if not then what would make them long lasting?