Who might be the cause of Yami getting mad in the 'yami gets mad fanfiction'?

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.

In a 'yami gets mad fanfiction', it could be that Yami discovers a betrayal. Suppose he trusted someone deeply in a magical world they inhabit together, and that person has been secretly working against him. This realization makes him extremely mad, and he has to decide how to deal with this traitor while also protecting his friends.

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.

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.

It could be Perry the Platypus, in a really unexpected turn. Maybe Perry has to keep some secrets from Phineas for his spy work, and one day those secrets are revealed in a way that makes Phin feel betrayed. This would definitely make him mad.

In the fanfiction, Yami suddenly falls ill. His friends notice his pale face and lack of energy. They quickly bring him to a healer. The healer diagnoses him with a strange fever. As Yami lies in bed, weak and delirious, his friends take turns to look after him, bringing him warm soup and medicine, hoping for his speedy recovery.

It could be that Ron's actions were causing problems within the Order of the Phoenix. If Ron was being stubborn and not following the plans or orders set by the Order, which Sirius is a part of, Sirius might get angry. He would be frustrated with Ron for not being a team player and potentially endangering the mission and the lives of others.

There could be a rival character, let's say Jack. Jack might be constantly provoking Zane, which eventually makes Zane mad.

Sasuke could be a possible cause. If Sasuke were to go back on his word about protecting the village or if he were to harm their friends again, Naruto would be pissed. Their relationship is complex, and Sasuke's actions often have a strong impact on Naruto.

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.