The Northwest Pillar is a pillar located in the Frozen Reaches near the Drake Tower that explains in undecipherable text how to kill the Two-Headed Dragon.
Background[]
The pillar can only be translated through use of the Deciphering Amulet. It reads "only a blade of fire can sever the heads of the Drake."
While traveling through the Frozen Reaches, Connor located the pillar and was able to read it using the Deciphering Amulet he had recovered from the Ice Lord's Stronghold after killing Thork. The pillar's instructions and the Flame Sword he had retrieved from the Impervious Ice allowed Connor to kill the Two-Headed Dragon and reach Paradise Lost.