Level 58
To print the values from 100 to 1, you can modify the for loop to start from 100 and decrement the value of $z until it reaches 1. Here's the updated code:
<?php for ($z = 100; $z >= 1; $z--) { ?>
<li class="swiper-slide"><span class="font-d-bld text-white text-active"><a href="bonushunt.php?ID=<?php echo $hunts[$z-1]->id;?>"><?php echo $hunts[$z-1]->id; ?></a></span></li>
<?php } ?>
Note that we're using $z-1 to access the correct index in the $hunts array, since arrays in PHP are zero-indexed.