Combination Attack - Both the heros and the bad guys. The most useful ones are Devistate and the elemental swords combos.
Complexity Addiction- Aside from the boxing match noted above, the villains in this game must have a kidnapping complex or something. You have to rescue Tina from bandits dressed like the mafia, Cody (the person-turned-lion-turned-into-a-gold-statue) from a circus performer, and you have to save Leona from... an empty warehouse below a random rich person's house. Note that the villains' main goal in life is to kill you so you can't stop the Big Bad.
Distressed Damsel - Both Tina and Leona have to be rescued before joining. In Leona's case, she's literally kidnapped right before your eyes right before she can join you just so you can save her. And that's just a matter of finding the right warehouse, rendering the whole thing utterly pointless.
Doomed Hometown - well, when you live on a volcanic island that houses someone who basically wants to destroy the world out of spite, what did you expect?
The Guards Must Be Crazy - Need to get into that big fancy town, but you're too young? Pay some guy with a jackhammer, tunnel under the wall and slip inside. Then you can talk to the guards and they'll treat you just fine.
Guide Dang It - To build a boat, you require a golden nail. Which you find stuck inside the wall of the builder's house.
Hyperactive Metabolism - Bread and plum-plums are roughly as effective as healing spells for the first portion of the game, and are perfectly usable in combat. You can even have one of your friends stick a loaf of bread into your mouth for you!
Ungrateful Bastards - The Mayor of Decatas and his followers; after you let them move into your village, they proceed to take over and kick you out of your own home.
What Kind of Lame Power Is Heart, Anyway? - Dan technically isn't an Aqutallion; he's a Wiseman whose purpose is to help unlock the others' powers, can't upgrade to an advanced class, and can't join in on combination attacks.
Heart Is an Awesome Power - Rather than elemental-based magic, he just blows up all your enemies at once, and can also heal everyone with a single spell.