WoW Transmog — Browse All Transmog Sets
Browse all 3,100+ World of Warcraft transmog appearance sets. Filter by expansion, armor type (Cloth, Leather, Mail, Plate, Cosmetic), and PvP sets. Track your wardrobe completion across all expansions.
Browse transmog sets from raids, dungeons, PvP, and quests across all expansions. Filter by armor type (plate, mail, leather, cloth) and source. Track which appearances you own and which you still need via Battle.net sync.
Battleplate of the Highlord
Plate set. Warlords of Draenor. Doesn't allow bottom half of a tabard through :(
Battleplate of the Highlord is a transmog reward obtained from the Cache of Nightborne Treasures, which is awarded through weekly event quests and dungeons.
Complete weekly event quests
Complete the weekly event quest "Emissary of War" marked with Heroic difficulty to receive a 
Cache of Nightborne Treasures.
Open your cache
Open the Cache of Nightborne Treasures to obtain Battleplate of the Highlord as transmog loot.
Tips
The item level of rewards from the cache is determined when the quest is obtained, not when it is completed or the cache is opened.