You’re looking for Purveyor Zo’kuul or Zo’sorg, both located inside The Enclave in Oribos
For mark of honor you can buy gear for transmogs from seasons (and previous additions, you also need to look for vendors from addons) and pvp gear reviews for the profession.
Play a lot of PVP modes - random Battlegrounds or arenas. Besides what Wednesday you can pick up one item from valua in Oribos