Maybe the baby is hungry. In many graphic novels, this is a common reason for a baby to cry.
One possible reason could be that she's lost in an unfamiliar place. In the Naruto universe, it's a dangerous world for a baby. Maybe she got separated from her parents during an attack on the village. Another reason might be that she's hungry or not feeling well. Just like any baby, she could be crying because she needs something basic like food or warmth.
One possible reason could be that he is lonely. In many fanfictions, Naruto is often ostracized as a baby due to the Nine - Tails inside him. He might be crying because he feels the lack of a warm, loving presence around him.
One possible reason could be unrequited love. In the fanfic, Chansung might be in love with someone who doesn't feel the same way. This could lead to a deep sense of sadness and cause him to cry. For example, he might have confessed his feelings but been rejected, leaving him heartbroken.
Perhaps he's feeling guilty about something that happened during one of his quests. Maybe he made a decision that had negative consequences for someone he cares about, and that's weighing on him. It could also be that he's just had a really tough encounter with a powerful enemy and is letting out the pent - up stress and fear through crying.
Maybe Wendy is crying because her favorite Pokemon got hurt in the fanfiction. It's really sad when a beloved Pokemon is in pain.
One reason could be the loss of a fellow shinobi. In the Naruto universe, comradeship is highly valued, and if Kotetsu were to lose someone close to him in battle or otherwise, it would be a very emotional moment that could lead to crying.
One possible reason could be Loki's sense of isolation. In many Avengers fanfictions, Loki is often portrayed as an outsider. He may cry out of loneliness, feeling that he doesn't truly belong anywhere, not even among his own kind. Another reason might be regret. Loki has done a lot of wrongdoings in the stories, and he could be crying over the consequences of his actions, like the harm he has caused to Thor or the people of Asgard.
Maybe he's missing his family. He's been away from them for a long time on the Argo 2, and homesickness could hit hard and make him cry.
Another possibility is that she had an argument with a friend. It might not even be Ron. It could be with Harry or another Gryffindor. She's very sensitive about her friendships and any conflict could make her cry.
One possible reason could be that the story was not engaging enough. Maybe the plot was too predictable or the characters were not well - developed.