Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Elysian Flame Crown Compares
Who It Suits
Cloth is the armor type Mage, Priest and Warlock wear. With Intellect, Elysian Flame Crown suits Discipline, Holy and Shadow Priest; Arcane, Fire and Frost Mage; Affliction, Demonology and Destruction Warlock.
Transmog Sets
Elysian Flame Crown is part of the transmog set Threads of Awakening (Priest, Mage and Warlock only). The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 221131 (221126 to 221136) were usually added in the same batch as Elysian Flame Crown: the same quest line, zone, vendor or reward set.