Set home page to last page of a certain category

you can use the per_get_posts filter hook to change the order of the query something like:

add_filter('pre_get_posts', 'filter_homepage_posts_order');
function filter_homepage_posts_order($query) {
    //only run is current page is home page
    if ($query->is_home) {
        $limit_number_of_posts = 5; //number of posts 
        $featured_category_id = get_cat_id('Reviews'); // by cat name...
        $query->set('cat', $featured_category_id);
        $query->set('posts_per_page', $limit_number_of_posts);
        $query->set('order','DESC')
    }
  return $query;
}