However, as the story progresses, Yugi might find his inner strength. He could use his dueling skills not just to win against opponents in the game but also to stand up to the bullies. For example, he might challenge the bullies to a fair duel and show them that he's not someone to be pushed around. His friends, like Joey and Tristan, might also step in to support him, which gives him more courage to face the bullies head - on.
Another possibility is a jealous rival. Maybe there's someone who is jealous of Gohan's power or his relationship with certain characters. This rival could do things to annoy Gohan and push him to the edge of his temper.
A new player on an opposing team could be the cause. This new player might be overly cocky and disrespectful towards Kuroko during a game. They could constantly taunt him about his lack of presence, which finally gets on Kuroko's nerves and makes him mad.
It could be Vegeta. Maybe Vegeta does something really underhanded like stealing Goku's senzu beans or trying to take all the credit for a victory that Goku also contributed to. Goku, being a fair - minded person, would get angry at such behavior.
One of his friends could be the cause, accidentally. Maybe a friend makes a deal with a shady character without realizing the consequences. This deal ends up putting everyone in danger, and Yami gets mad at his friend's naivete and the mess they've created.
He might become withdrawn at first. Since he's used to being in control and having a certain dynamic in their relationship, Bella's anger could shock him into pulling back. He could go off on his own for a while to think about what he did wrong.
Definitely Doofenshmirtz. He could mess with one of Phineas and Ferb's inventions in a way that really ticks Phineas off. Like he might use one of his -inator devices to turn their amazing flying machine into a pile of junk. Phineas would be furious and would then set out to fix it and get revenge on Doofenshmirtz.
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.
In this kind of fanfiction, one possible scenario could be that Yugi is bullied at school. Maybe some jealous classmates pick on him because of his unique card - playing skills. They could steal his cards or make fun of him during lunch breaks.
One popular type might be those that explore the reactions of the other characters. For example, his friends could be in shock at first but then become very supportive. They might help Yugi with various tasks during the pregnancy.