Oops, sorry, wasn't sure.

Oh I think I see how to at least get your mastery text back. Move your text for displaying mastery, ie this stuff

<h1>Mastered</h1> <h2>OTPs and Friendships</h2> <center> <?php show_mastered('parings','1'); ?> </center> <h2>Specials</h2> <center> <?php show_mastered('parings','2'); ?> </center>

to right under this line

<?php } elseif ($_SERVER['QUERY_STRING'] == "mastered") { ?>