You Can Use Selector "+"
HTML
<a id="tooldrop">HOVER ME !</a>
<ul id="dropea">
  <li>ONE</li>
  <li>TWO</li>
</ul
CSS
    ul#dropea li{
        background-color: red;padding: 10px;opacity: 0;transition: all 0.3s ease-in-out;
    }
    #tooldrop:hover + ul#dropea li {
      transform: rotate(0) scale(1);
      opacity: 1;
    }
===========================================
JUST ADD "+" EVERY NEW ELEMENT
HTML
<a id="tooldrop">HOVER ME !</a>
<div class="block"></div>
<ul id="dropea">
  <li>ONE</li>
  <li>TWO</li>
</ul>
CSS
   ul#dropea li{
     background-color: red;padding: 10px;opacity: 0;transition: all 0.3s ease-in-out;
    }
    #tooldrop:hover + div.block + ul#dropea li {
      transform: rotate(0) scale(1);
      opacity: 1;
    }
ExteraDex