Final Fantasy Crystal Chronicles: Ring of Fates: I am a Selkie!

Further through the game, after a key character has died, I've now got a party of four traipsing around, including one of each tribe. The king's apparently under the spell of an evil yuke, who's pretending to be one of my party. I'm now battling through a flooded complex after finding my lilty friend, and have found a big fish who I wish to be rid of. He is killing me lots.