Best Boss Ever: When the two parties meet and fight for control of the spirit stones. You must pick one party you (the player) side with... and then you fight the other. You're literally fighting the other party you've been controlling for the entire game - and they will use the same techniques you've been using. It may be nothing after you were forged in the fires of Demon Droguza and Darkham, but damn if it isn't fun.
Game-Breaker: Bebedora. She can just take any common enemies she wants and make them fight for you. She can only control two at a time, but whenever one dies, she can replace it with a new one.
Goddamned Bats: The Ninja enemies. High dodge rates and some have one-hit-kill techniques.
Densimo betrays Darc to the Drakyr. But he doesn't stop there, oh, no. He adds to his comeuppance by EATING the cute little firble Darc's been hiding.
What is the first thing Darkham does after obtaining the Flying Castle? Nuke Cathena, a city populated by humans, as revenge because its leaders refused to aid him when the Deimos attacked his homeland.
That One Boss: Demon Droguza. His physical attack power is through the roof, he has a sweeping tail laser that slices across the midpoint of the battlefield (where you will be caught, unavoidably), and can fire a giant energy ball that goes boom on your little cluster of fighters and nukes roughly half of their HP on a normal, non-grindfest playthrough. And your healer will very likely die. Add in the fact that the resurrection spells aren't likely going to be available to you at this point....
They Wasted a Perfectly Good Plot: Kharg and Darc being twin brothers could have been used as a bigger plot twist, but it's unceremoniously given away during Darc's first chapter.
The Woobie: Darc, he has to bury BOTH his parents!
