Cat nip is extremely useful, especially againsts fiends with 100,000+ HP. It allows the user to do 9,999 damage each time when the character is in critical health (yellow).
The mascot dressphere is important because it has auto-shell and auto-protect, as well as ribbon. You get that automatically if you receive every episode complete in chapter 5.
Another good accessory is Iron Duke. You get that for defeating a certain somebody with 999,999 HP. It raises many of the stats.
