The thought occurred to me, could Prince Camarril, whoms tomb has the location of the Mythic Dawn's hideout on it, be a bastard child of Camoran and Dragonborn emperor (possibly Reman or even earlier?) lineage and a descendant of Mankar? This could then explain how he could wear the Amulet.

I just think the names Camarril - Camoran are awfully coincidental...

Doesn't he only wear the amulet in his 'paradise'?

If it's a magically created place or a splinter of Oblviion, then he could be able to bend the rules.