To defeat the Dread Knight, use Tess's Feeble II spell to greatly reduce the his high attack power. Keep Felis in case you need to use an item or heal with Restoras. Attack the Dread Knight with constant attacks from Lance and Goken. If you want to prepare to use a Group Lunability, when you are steadily reaching 500 make Deliza and Tess ready for a Group Lunabilty ahead of time. Use Deliza's Last Wind Lunability as it does the most damage.