The Pale Rider
The Pale Rider is a Rank S Heavensward Elite Mark found in The Dravanian Hinterlands.
Killing the Elite Mark will reward the player up to 
100 Centurio Seals, 
100 Allagan Tomestones of Poetics and 
30 Allagan Tomestones of Aesthetics.
Coordinates
The Dravanian Hinterlands
(x26,y28), (x??,y??), (x??,y??)
Spawn Conditions
Trigger
Assuming his random timer is up Pale Rider has a chance of spawning when a "Treasure Coffer" is opened from Level 60 Treasure Hunt Maps.
Time
Over 60 hours????
Additional Information
Levequest Treasure Coffers are said to work but no confirmation.
Description
"Another request sent by a Sharlayan scholar from the safety of his homeland. The fellow's uncovered an ancient prophecy, saying that in the end of days, a deathly knight will rise from the grave and bring death and destruction to Dravania atop an ashen steed.
If the scholar is right, and this "end of days" does indeed refer to the Seventh Umbral Calamity, then this supernatural horseman should already be among us, but I don't see any death and destruction around here. Well, no more than normal, anyway...
Honestly, I think it's all a pile of chocobo plop. There was an adventurer passed through here the other day, said she'd seen a headless horseman out in the hinterlands when she was hunting for treasure...but believe you me, you can trust those looters as far as you can throw them!