Disciple of Sun  

Spawned by killing the sun revenants in the fort ruins on top the plateu. He spawns in front of the platform and is non-agro and cons indifferent.

He says "I see you come in search of our ways. How can one such as yourself think that you have the power and pureness to challenge a Disciple of the Celestial Order? Very well though, if you wish to [challenge] me, I shall enlighten you."

At which point I would assume that saying "I wish to challenge" begins the fight.

Leaving him alone and killing sun revenants just outside the fort would emote "Who dares to disturb the meditations of the Disciples of Sun" upon their death.