One common theme could be the exploration of their relationship dynamics. It might involve how they interact, whether it's in a friendly way or with some underlying tension.
I'm not sure about specific 'once ler x greed ler fanfic' off the top of my head. You could try searching on popular fanfic websites like Archive of Our Own. They usually have a wide variety of fanfictions in different categories.
The reaction of site.com to manga can vary greatly. It could be highly supportive, promoting and featuring manga prominently. Or it could have a more limited engagement, only showcasing selected titles. It all depends on their business strategy and target audience.
I wouldn't recommend looking for unblocked manga sites as they often violate copyright laws and can be risky. It's better to use legal and authorized platforms to enjoy manga.