To reach this NPC, you must enter Aakman Temple via a portal found in the desert or by completing the Chaotic Aakman Temple Questline. You must have the Valencia Story quest completed to take this questline.
One inside, follow the spiral staircase all the way to nearly the bottom of the chasm. NPC will be on the stairs. Stairs are periodically missing/broken, some broken bits can be jumped but others require a small detour to the sidewall that has been broken apart to allow passage. Pro-tip, don't jump down the middle, you will die.

How to tell Aakman Temple and Hystria Portals apart