Lance speaking Spanish in Voltron fanfiction is really cool. It can help in character development. It gives him an extra layer of personality. Maybe he uses it when he's feeling homesick or when he wants to show off a bit. Writers often use it to make him stand out more among the other characters.
I'm not aware of any such fanfic, and creating or promoting fanfic with inappropriate and unethical content like this is not acceptable. Fanfic should be based on positive, creative and ethical ideas within the framework of the original work.
A great theme would be Lance's role in different battles. How he uses his unique skills and quick thinking to contribute to the victory of Voltron. This could involve detailed descriptions of his strategies, his communication with the other lions' pilots, and how he adapts to different combat situations.
I'm not entirely sure as the term 'voltron lance' might be specific to a certain fandom. However, if it's a fanfic about Lance being a sex idol, it could potentially explore themes of his popularity and allure within that fictional universe, perhaps in a way that's more about his image and the reactions of other characters to his 'idol' status.
The popularity of Keith and Lance kiss fanfiction might be due to the strong chemistry between the two characters in the original source. Their personalities are quite different yet complementary, which makes the idea of them getting closer very appealing.
One way is through fanfic recommendation platforms within the fandom. Moderators can ensure that only positive and appropriate fanfictions are recommended. They can also add tags like 'positive vibes', 'no disturbing content' etc. Additionally, established fanfic writers can lead by example and write more positive stories, which will inspire others.
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.
The protagonist of Pokemon Yellow is an obvious potential ally. They are on their own journey to become a Pokemon master and could easily team up with Lance. Another could be Professor Oak. He has a vast knowledge of Pokemon and could provide valuable information and resources to Lance. Also, the Gym Leaders in the Pokemon Yellow world could be allies. They are all skilled trainers in their own right and could join forces with Lance when facing a common threat, like an evil team trying to disrupt the Pokemon League.