The bad guys (Fing, Fang, Foom, Ting, Tang, Tomb, Ding, Dang, and Doom) are pretty tough but they have a hidden weakness.
Some bad guys are allergic to physical spells. Some bad guys are allergic to magical spells. And some bad guys alternate their allergies during a battle.
Some spells cause physical damage. Some spells cause magical damage. And some spells do both flavors of damage (or no damage at all).
See if you can figure out which bad guys are allergic to which spells. After you do the bad guys are much easier to deal with!