The high priest definitely has some potent magic, supporting him, trying various tricks to slow Draiss, as he retreats, especially once he sees direct assaults won't work, including attempting to open a bit, beneath Draiss, and conjuring his own Blade Barrier. Unfortunately, he doesn't come up with anything effective, by the time he retreats right into Tiamat's jaws, her five dragon heads descending as one, each grabbing a different limb, and pulling. The green head shouts "Hah! I win!" as Draiss notices that it has the limb with the largest section of the torso remaining; apparently a rather morbid version of a wishbone. The priest is devoured in a few seconds, and Tiamat grins at him. "That was simple enough, don't you agree?"