Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Night Dreamer Robe Compares
Who It Suits
Cloth is the armor type Mage, Priest and Warlock wear. With Intellect, Night Dreamer Robe suits Discipline, Holy and Shadow Priest; Arcane, Fire and Frost Mage; Affliction, Demonology and Destruction Warlock.
Transmog Sets
Night Dreamer Robe is part of the transmog set Vestments of the Manasinged (Priest, Mage and Warlock only). The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 139089 (139084 to 139094) were usually added in the same batch as Night Dreamer Robe: the same quest line, zone, vendor or reward set.