Atticus and Zane are likely characters created within the fanfiction world. They could be friends, colleagues, or even rivals. Without more context from the actual fanfiction, it's hard to say exactly who they are. But they are the main characters involved in this shaving - related situation.
They are likely characters within the context of the fanfiction. Without reading it, it's hard to say exactly who they are. They could be original characters created for this fanfiction, or they could be characters based on an existing fandom, like a book, movie, or TV show.
Well, it could be that in this fanfiction, Atticus has a particular reason for getting Zane to shave. Maybe Zane has a really wild beard or facial hair that is causing problems. Atticus could see that shaving would make Zane more presentable or more acceptable in their community or among their friends. It could also be part of a character - development arc for Zane, where shaving is a symbol of change or growth, and Atticus is the catalyst for that change.
It could be his rival. Rivals in Yu - Gi - Oh are always trying to one - up each other. If his rival manages to steal a rare card that Zane has been eyeing, or if the rival taunts Zane about a recent defeat, that would surely make Zane mad.
Maybe in the fanfiction, Atticus and Zane are friends, and Atticus is just being a good friend by suggesting Zane to shave. Zane could be going through a rough time and has let his appearance go. Atticus, seeing this, tries to get him to shave as a way of getting him to take better care of himself and regain his confidence.