Gnashing of teeth
At this point, the hero has normal sized teeth, which can be clashed together for moderate damage.
At this level, the hero's teeth have become very brittle so that much more teeth bits fly at the enemy.
At this level, the hero's teeth have become very sharp so the bits cut and slice the enemy.
At these levels, the hero's teeth have instead been replaced by small detachable grenades that fly out when they clash together.