"There is rumor of an ancient relic handed down by the Antepyrovians that suspends the normal aging process. But what length would the Children of Mann go to, to obtain such an object? Would anyone be safe wearing something so coveted?"
I hope this will be like a Holy Grail in our world, more a mystery than actual relic to obtain.
"would be an EPIC end-game find, effectively making your character immortal and not subject to the normal aging effects!?"
Definitely not an EPIC end-game object, which would be available eventually to large mass of players. That would ruin the concept of the game.
On the other hand, a one on the realm item, obtainable by series of epic, chain quests. With the reward of being recognised as a most famous relic hunter / discoverer / crusader * you name it. And given the official parade, show, presentation at the royal court. Well that would give some nice roleplaying, some well deserved recognition, and of course knowledge to the whole world of shady people the name of the person that is in possession of world's most sought relic.
I can imagine those theft contracts, those assassination plots and political arrangements.