This WoW set features the full Crystalforge transmog, which is the paladin tier 5 raid set. Crystalforge is obtained by looting armor tokens from various Burning Crusade bosses. These tokens can be traded for set pieces via Shattrath City tier vendors.
How to Get Paladin Tier 5? By slaying Serpentshrine Cavern and The Eye (Tempest Keep) bosses.
Are There Multiple Tier 5 Transmogs For My Class? No, some classes do have multiple tier 5 sets (depending on their class trees), but every tier set variation features the same exact transmog look. For example, the paladin has a different set for retribution, holy, and protection, but all three sets share the same exact model and color variation. (Hunter, Mage, Rogue, and Warlock feature only one tier 5 set)
How Many Set Pieces?  Helmet, Shoulders, Chest, Hands, and Pants
Paladin Tier 5 Transmog: [Drop Locations]
Note: Paladins have three different sets with the same exact look. Tier 5 paladin armor tokens can be used to purchase any of the set pieces.
Head: Helm of the Vanquished Champion by slaying Lady Vashj in Serpentshrine Cavern.
Chest: Chestguard of the Vanquished Champion by slaying Kael’thas Sunstrider in The Eye.
Hands: Gloves of the Vanquished Champion by slaying Leotheras the Blind in Serpentshrine.
Legs: Leggings of the Vanquished Champion by slaying Karathress in Serpentshrine .
Tier 5 Set Vendors: [24,27] Kelara (Aldor) OR [44,91] Veynna Dawnstar (Scryer) | ~Shattrath City~
Set Name: Crystalforge Armor (hover for set bonuses)
Shoulder: Crystalforge Shoulderguards
Chest: Crystalforge Chestguard
Hands: Crystalforge Handguards
Legs: Crystalforge Legguards
Set Name: Crystalforge Battlegear (hover for set bonuses)
Shoulder: Crystalforge Shoulderbraces
Chest: Crystalforge Breastplate
Hands: Crystalforge Gauntlets
Legs: Crystalforge Greaves