Expandable post with different Catagories?

I looked everywhere on the forums and tried to search through google but I didn’t find any answers.
Want I want to set up is a way to have a list of posts sorted by categories, shown through rows. I can get a list setup no problemo, but the problem is connected the post category to each individual row, and having only a certain number of posts shown when clicked.

it’d also be great to have a count-up in the title as shown below 🙂

A good example of what I mean is at wuxiaworld.com

Any help is much appreciated!