Dark Cloud

Naturally, this is the hardest fight in the game, so go in with your strongest weapons fully repaired and plenty of premium chicken, revive powders, and stand-in powders.

This is a two-part fight. Use Toan for the first part. Stay on the run constantly, stopping only when a hand comes up behind you to turn around and hit it. Set the attribute of your weapon to the same color of the eye on the back of the hand to damage it. Once you've hit the hands enough, the genie will start firing beams at you out of his forehead. At this point, switch to Xiao or Ruby to lock on his face and hit him until he goes down, dodging as necessary.

The second part of the fight gets a bit sticky because there's not a lot of room at the beginning. He'll spawn some skeleton creatures that you need to take out with Toan, and it's very easy to die here because he's shooting a powerful beam himself while you're stuck between his skeletons. I don't know if anything particular spawns it besides getting far away, but when I ran as far away as possible, its attack changed to sending some beams along the ground that were easy to dodge, so I just stayed way back there, locked onto its face with Xiao and kept hitting it from a distance until it died.

The trophy will fire as soon as you make the killing shot.