Combine the results of two loops [closed]

Yes it is. First you have to combine the results in one array:

$all_posts = array_merge( $related->posts, $features->posts );

Now, let’s sort the array items by date:

usort( $all_posts, function( $a, $b ) {

    return strcmp( $b->post_date, $a->post_date );
} );

Finally, do the loop:

global $post;
foreach ( $all_posts as $post ) {
    setup_postdata( $post );
    // use the template tags here: the_title(), the_content(),…
}
wp_reset_postdata();