The moment when Matsuda accidentally says something really stupid in front of L and the rest of the task force. Everyone just stares at him in disbelief, and it breaks the tension in the room which is usually filled with high - stakes investigations.
One funny moment could be when a person attempts a complex pose like the wheel pose and ends up looking like a wobbly wheel instead of a graceful one. It's really comical.
In Stellaris, there are often funny species traits. For example, I once encountered a species that had the trait of being extremely clumsy. Their ships would constantly bump into each other in their own fleets. And during a joint operation with an allied empire, they accidentally fired on their own allies because they misread the battle orders. It was chaos but also very funny. Also, there was a time when a pre - ftl civilization in my game sent a 'spacecraft' made of cardboard and tinfoil into space, thinking they were exploring the cosmos.
One funny moment was when a Hunter tried to use a spell they found in an old book. They mispronounced every single word, and instead of some powerful magic, they made a bunch of feathers rain down from the sky. It was so unexpected that everyone around just burst out laughing.
Ryuk would probably just be amused. He is a Shinigami who has seen a lot in his existence. Fanfiction is just another strange human creation to him. He might chuckle at some of the more outlandish ideas in the fanfictions, like a character having superpowers beyond the Death Note.
Misa would likely be excited. She is a big fan of Light and the whole 'Kira' concept. In fanfiction, if there are scenarios where she has more power or a closer relationship with Light, she would be all for it. However, she might also get jealous if there are other female characters getting too close to Light in the fanfictions.
One of the funniest moments could be when a clumsy knight tries to joust but misses his target completely and ends up falling off his horse into a mud puddle. It's a classic comedy scene that would surely bring laughter.
Imagine the soldiers trying to disguise themselves in the local area. They end up looking so out of place and comical that it's a funny moment. Their attempts to blend in but failing miserably due to their military - bred habits and lack of local knowledge add a touch of humor to the otherwise intense Saving Private Ryan story.