In this guide, I will share with you how to get the achievement above.
Do note that you need to unlock Enkanomiya in order to obtain this achievement.
Teleport to the Serpent’s Bowels south waypoint and head northwest.
Pick up the sword under the waterfall.
Teleport to Byakko Plain south waypoint and head northwest.
Interact and place the sword on the blade mound to get the achievement.