Some Tumblr blogs are dedicated to sharing and discussing yaoi fanfictions. You can search for relevant tags such as 'Kagami x Aomine yaoi' on Tumblr. But be aware that the content quality can vary greatly, and not all of them may be well - written or in line with what you expect.
You can try looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions, and there might be some about Megatron and Starscream in a yaoi context. Just use the search function on the site.
Another place could be Fanfiction.net. However, the search functionality might be a bit less precise compared to AO3. But it still has a large collection of fanfictions. You may need to dig a bit deeper and use more specific keywords in your search, like 'Erik x Charles slash' which is sometimes used to denote YAOI content.
There are also some specialized manga or story websites that might feature yaoi stories. For example, MangaDex may have some yaoi manga which can be considered as a form of yaoi story in visual form. You need to check the tags and categories carefully to find what you want.
Another option could be Fanfiction.net. However, the tagging system there might not be as refined as AO3. But still, it's worth a shot. Look for the relevant categories or use the search function to hunt for Altair x Malik yaoi fanfictions. Some authors might also post on their personal blogs or Tumblr, so you could also search there.
Some other platforms that might have such fanfiction are FanFiction.net. However, the content there can be a bit more hit - or - miss. You might have to dig through a lot of different stories to find the good Raphael x Leonardo yaoi ones. Another option could be Tumblr. There are a lot of fan communities on Tumblr that share and discuss fanfiction, and you might be able to find some links or even full stories there.
Finding 'beerus yaoi fanfic' can be a bit of a search. Firstly, Archive of Our Own (AO3) is well - known for its extensive fanfic library. There are also smaller, more niche fanfic communities that might have such works. You could also try searching on social media groups dedicated to the fandom of the work Beerus is from. Sometimes, fans share their fanfictions there. But be aware that not all content on these platforms may be easily accessible or of high quality.
You can find some great yaoi stories on websites like MangaDex. It has a large collection of manga, including yaoi works. Just search for the genre and you'll get a list of available stories.
You can try fanfiction websites like Archive of Our Own (AO3). There are a large number of Naruto fanfictions there, including those with Akatsuki and Naruto in yaoi relationships. Just use the search function and type in relevant keywords to narrow down your search.