Essential
Frostallion Noct Bounty Token
Legendary1g
Proof of defeating [Frostallion Noct, Legendary Steed of Darkness]. Simply possessing it permanently increases the stats of the Pals in your team.
Where to find
No single source is catalogued for this one. Items like it are usually gathered in the field, pulled from dungeon chests, or bought from wandering merchants.