Thread:FourSevensRiolu/@comment-32293731-20190618235521/@comment-39280914-20190620000833

It seems to follow the usual rarity tiers for games: https://tvtropes.org/pmwiki/pmwiki.php/Main/ColorCodedItemTiers

Except instead of Epic, it's "Heroic" (probably to not confuse with the Epics)