Horde Flag of Victory
Drops from Coliseum Champion's Spoils. This flag is obtainable via Highmaul Coliseum. It's looted from the bag rewarded from Fight, Kill, Salute!
The Horde Flag of Victory is a toy dropped from 
Coliseum Champion's Spoils, the bag rewarded for completing the Fight, Kill, Salute! quest at the Highmaul Coliseum in Draenor.
Guide awaiting review
Build Gladiator's Sanctum
In your Draenor garrison, construct a level 3 Gladiator's Sanctum. To unlock the level 3 plans, you must complete The Bone Collector, which requires collecting 4,000 
Broken Bones.
Farm Broken Bones
The fastest method to collect the 4,000 Broken Bones is to join an Ashran raid group and accumulate kills alongside other players in the zone.
Accept Call of the Gladiator
Once your level 3 Gladiator's Sanctum is built, pick up the Call of the Gladiator quest from your garrison, which unlocks access to the Highmaul Coliseum.
Complete Fight, Kill, Salute!
Fight, Kill, Salute! is a follow-up quest to Call of the Gladiator and is completed inside the Highmaul Coliseum. Upon completion, you receive the Coliseum Champion's Spoils bag, which has a chance to contain the Horde Flag of Victory.
Tips
The Highmaul Coliseum is unavailable to players above level 100, so you must lock your XP at level 100 to participate. Queue times are extremely long, so organizing premade groups with other XP-locked players is the only reliable way to complete this content.
