This lore can be found on Korriban.
X: 44, Y: 489
The secrets behind Tulak Hord’s great power were many, and they all but vanished from the galaxy with the Dark Lord’s death. Generations of Sith have obsessed over unearthing his ancient teachings and artifacts, but Tulak Hord hid them well. Of the relics recovered successfully, the mask of Tulak Hord is most recognizable. Darth Revan discovered this relic in Tulak Hord’s tomb while searching for the Star Forge space station, though both the mask of Tulak Hord and the mask of Darth Revan have disappeared since. In recent years, Tulak Hord’s lightsaber was unearthed on Dromund Fels by Darth Marr before his ascension to the Dark Council. Despite these discoveries, Tulak Hord’s greatest treasures still lie locked away in the far corners of the galaxy, waiting for a new master to claim their power.