First seen in build 12.0.7.68887 (Midnight (patch 12.0.7)).
Related
Soul-Siphon Mantle Game Data
Appearance
In the Appearances collection, Soul-Siphon Mantle is listed as Boss Drop. Appearance IDs: 34816, 34799, 34791, 34841. 3 other items wear the same appearance:
Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Soul-Siphon Mantle Compares
Who It Suits
Cloth is the armor type Mage, Priest and Warlock wear. With Intellect, Soul-Siphon Mantle suits Discipline, Holy and Shadow Priest; Arcane, Fire and Frost Mage; Affliction, Demonology and Destruction Warlock.
Transmog Sets
Soul-Siphon Mantle is part of the transmog set Grim Inquisitor's Regalia (Warlock only), which the Appearances collection lists in 4 versions. The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 151949 (151944 to 151954) were usually added in the same batch as Soul-Siphon Mantle: the same quest line, zone, vendor or reward set.