Well, first off, the 'lemon' part which implies mature content can be a big challenge as it may not be acceptable on most platforms. And writing a crossover also requires a good understanding of both the Kagome - related universe and the other universe it's being crossed with. You need to blend the characters and storylines in a believable way.
One possible plot could be that Kagome somehow gets transported into the Lab Rats' world. Maybe she mistakes their high - tech lair for a strange youkai (demon) lair at first. The bionic heroes could be initially suspicious of her, but then realize she has her own kind of 'powers' in the form of her spiritual abilities and her sacred arrows. Together, they could team up to fight a common enemy, perhaps an evil scientist who wants to use both Kagome's spiritual energy and the bionic technology for his own malicious purposes.
First, research about aro experiences. This helps in creating an authentic aro original character. Then, focus on the character's growth and development outside of romantic relationships. For example, their friendships or their pursuit of personal hobbies and goals. Also, avoid making the aro oc a stereotype. Give them a complex personality.
In a crossover with 'Sailor Moon', Sailor Mars would be a great character for kagome to interact with. They both have powers related to spiritual energy and fire. They could learn from each other's combat styles and magical abilities, and perhaps team up to fight a common enemy that threatens both their worlds.
Another plot could involve kagome in the 'Fullmetal Alchemist' universe. Since she has experience with magic and the supernatural, she might be able to assist the Elric brothers in their search for the Philosopher's Stone. She could use her knowledge of different realms to find clues that they missed.
Most mainstream platforms don't allow 'lemon' fanfiction because it usually contains inappropriate content. But if you're interested in Kagome crossovers in general, you can check out fanfiction.net. Just keep in mind to avoid any works that violate the site's terms regarding adult - like content. There are likely to be some great crossovers with Kagome from different anime or fictional universes there.
The characters would interact in some really interesting ways. Kagome, being from a more traditional and magical world, would bring a sense of wonder to the Lab Rats. She could show them her techniques for fighting demons, like her acrobatic moves and her use of the sacred arrows. The Lab Rats would share their high - tech gadgets with her. For instance, they could let her try out their super - speed or super - strength enhancements. There would be some cultural clashes too. Kagome's more formal and respectful way of speaking compared to the modern and sometimes sarcastic speech of the Lab Rats would lead to some humorous exchanges.
I'd recommend 'Peter Parker's Hidden Talents'. In this one - shot, Peter discovers a new ability that has nothing to do with his spider - powers. It's a really creative take on the character. The story is short but full of interesting twists and turns.
One interesting Nalu Lemon one - shot could be about Natsu and Lucy getting lost in a magical forest and sharing an intimate moment. Another might involve them having a beach day that turns into a romantic encounter.
Common themes include the power of understanding. In these one - shots, Hermione tries to understand Snape's motives and actions, and Snape in turn comes to understand Hermione's intelligence and determination. Another theme is the idea of second chances. Snape, with his complex past, is often given a second chance at a more positive relationship through his interactions with Hermione. And the theme of mutual respect also pops up, as they learn to respect each other's skills and qualities.