Maybe Zane and Syrus get trapped in a strange virtual world created by some glitch in the digital system. They have to rely on each other's skills to find a way out. Zane's logical thinking and Syrus's knowledge of the digital realm might be combined to overcome the various obstacles like malfunctioning programs and security barriers.
It's quite normal. In a fandom, people are interested in different aspects of the characters. Zane might be curious about Syrus's backstory, relationships, or potential storylines that fanfiction writers have created. It's just another way of engaging with the fictional world they are part of.
Perhaps Zane is a big fan of Syrus himself and by reading the fanfiction, he gets to delve deeper into the Syrus - centric stories. It could also be that he enjoys the creativity of the fanfiction community and how they expand on the Syrus character in ways the original work might not have.
At first, their relationship might become strained. Zane's anger could make Syrus confused and a bit scared. Syrus might try to avoid Zane, not knowing how to deal with his anger.
In the Yu - Gi - Oh fanfiction, when Zane gets stuck with Syrus, they might have an intense duel training session. Zane could be super strict with Syrus, pushing him to improve his dueling skills. Maybe Zane would share some of his top - secret dueling strategies that he's developed over the years.
One possible reason could be jealousy. Maybe Syrus is getting more attention in the fanfiction world, and Zane, being a proud character, doesn't like that. For example, if Syrus is praised for his skills while Zane feels overlooked, it can make him mad.
Maybe he'll be really bored at first. Fanfictions can be quite strange sometimes, especially if it's not something he's interested in. He might try to find a way to stop watching, like looking for an exit button or asking someone for help.