Well, perhaps there could be a plot where the enemy somehow uses Keith's baby form to their advantage. They might think he's more vulnerable and try to capture him. But the team, of course, would do everything to protect him. And as Keith is a baby, he might start to show some new, innocent behaviors that gradually melt the hearts of the more stoic team members like Allura.
A plotline could also involve Keith's memories as an adult still being somewhat intact in his baby mind. So, he might try to communicate with the team in his own baby - like ways, like making certain noises when he sees something related to the cause of his transformation. The team would then have to decipher these 'baby signals' to solve the mystery and turn him back to normal.
I'm not sure of the exact title, but I once read a fanfic where Keith turns into a girl and it was really interesting. It had a lot of character development for Keith. The story started with the sudden transformation and then went on to show how he coped with things like having to wear different clothes in the Voltron base. His interactions with Lance also changed in a really unique way, as Lance was initially quite flustered by the change but then they developed a deeper bond based on mutual understanding.
The team as a whole would become closer as they united to take care of Keith. His transformation into a baby would bring out different sides of each character. They'd have to rely on each other more, communicate better, and work together in new ways. For example, they'd need to share babysitting duties, which would lead to more interactions and a deeper understanding of each other.
One common theme is identity. Keith has to figure out who he is now that he's in a different body. Another theme is acceptance, both self - acceptance and acceptance from the team. For example, in many of these fanfictions, Keith struggles with accepting his new form at first, but as the story progresses, he starts to embrace it. And the team also has to accept this new version of Keith.
One possible plotline could be that Keith is kidnapped by an enemy force. His friends then embark on a dangerous rescue mission, facing various challenges along the way. Maybe they have to infiltrate a heavily guarded enemy base to find and free him.
Well, the plot could involve his friends or comrades having to take care of him as a baby. Maybe they struggle to figure out how to feed him the right things or keep him entertained. For example, they might try different alien foods to see what baby Keith will eat.
A lot of the fanfictions about their kiss also explore the reactions of the other characters in the Voltron team. Some might be supportive, while others could be initially shocked or confused. The kiss can also be a symbol of a new era in the team's dynamics, as Keith and Lance's relationship changes. It can lead to interesting storylines about how the team adapts to this new development.
One possible plotline could be Keith's struggle to adapt to his new female body. He might face challenges in how others perceive him now, especially among his friends and allies. For example, some might treat him differently, either with more protectiveness or with new - found romantic interest. Another plotline could involve Keith exploring the differences in how society treats women compared to men in the context of this fictional world. He could use his new perspective to fight for gender equality within the story's setting.
One possible plotline could be Keith growing up not knowing Lotor is his dad. Then, through some series of events in the story, like a battle or a discovery in an ancient ruin, he finds out the truth. This could lead to a lot of internal conflict as he has to come to terms with who his father is, considering Lotor's actions in the original series.
One alternative could be 'Voltron Keith and the Mysterious Alien Artifact'. This kind of fanfiction could involve Keith's encounter with a strange and powerful artifact, and how he and the team figure out its purpose and deal with the consequences. It's a much more positive and engaging theme compared to the disturbing one.
A plotline could be that Keith is an undercover agent or spy, and being a girl would put her at risk in her mission. So she pretends to be a boy. As the fanfiction unfolds, she has to balance her real self and her false identity while also dealing with the challenges of her mission and the people she meets during it.