The Strongest Bond
Defeat someone you care for within three and half minutes.

This battle occurs at the end of your third playthrough. You will need all 30 weapons to trigger it, skip all cutscenes. Hit the enemy with two magical attacks and she will collapse to the ground, a barrier and two magical points will appear. There is no way to destroy the barrier or magical points and a 20 second unblockable barrage of magic will be inflicted on you. Run around to avoid getting hit or stand on the bed in the far end of the room. After it stops run up to your enemy and slash her with your sword until a cutscene plays, after which the trophy will unlock.

Important Note: If you didn't obtain the trophy don't choose option 2 after the battle, you'll have to start the game from the very beginning again!