The line about only Septims wearing it is false. The first living person to wear the amulet was Reman Cyrodiil who has no biological connection to the Septims aside from the fact that him and Tiber were both Nords.

On the wiki page for the Amulet, it says that only the ruler or king can wear it, but with Martin, I don't see how Mankar could wear it.

My guess is that because he is in his Paradise in Oblivion and not on Tamriel he can wear it either because 1.) He can do what ever he wants in his own Paradise or 2.) He can wear it because he is actually ruling the Paradise

Does it specifically mention Cyrodiil on the wiki page? As Mankar is the son of the Cammoran Usurper who ruled Valenwood and much of Hammerfell at one point.

Edit: I checked the page, the exact requirement to wear the amulet is unknown.

Mankar Camaron wears the Amulet outside of Paradise, too. Namely the first time you see him. (In Dagon's Shrine)

Firstly, we need to recognize the Amulet's origin. The Amulet was created by the Ayleids for an unknown purpose. Soon, Akatosh or Shezarr then forged the Covenant with Alessia and her descendants. (Only one of relation of Alessia and not Tiber Septim may wear it) The Amulet confirmed the legitimacy of Cyrodiil's rulers. One King Hrol found the Amulet by tracking down Alessia's spirit, who was wearing the Amulet. At that spot, an infant Reman Cyrodiil was discovered with the Amulet on his forehead. (So Hrol and Alessia had a child assumingly ) The Amulet of Kings gave the Reman Dynasty legitimacy and power to rule. When an emperor comes to power, in the ritual to become emperor, the new monarch is soul-linked with the Amulet and the monarch lights the Dragonfires. Tiber Septim gained legitimacy to rule through finding the Amulet in a tomb. So, the Septims had no relation to the Remans, so they had no relation to Alessia, but, Since Tiber Septim rediscovered the Amulet, he gained the power to rule, and became a descendant of Alessia by doing so. So, Uriel, through Tiber Septim, became emperor.

By taking the Amulet, Mankar might have become a descendant of Alessia, even though unrightfully.

I assume three things:

1) The emperor did not intend for you to be an heir.
2) The throne is still available for a rightful heir.
3) You were given it and you have not obtained it like King Hrol or Tiber Septim.

...
Actually that theory is pretty good, but my question is why then doesn't your character get to wear it, since it was willingly given by the Emperor himself?

Because you did nothing special, excpet wake up in a prison cell that was supposed to be off-limits.

Well if we are going to get technical here, fine.

Mankar didn't do anything special other than have taken out of a wooden box by one of his subordinates. :lol:

Mannimarco didn't do anything special other than make himself a lich. >.>

Please don't use that smiley eccsesively, as it takes the humour from things truly worthy.

See that's my whole point too.

All through the quest everyone keeps saying that "only a Septim can wear the amulet"
Then you see Mankar wearing TWICE!
Im sitting here thinking, Did one of the Emperor's sons survive, if so why would he being stealing the Amulet?

I just think that it was a "blopper" on Bethsheda's part.

I think they made the Amulet visible on Mankar so you would know were the Amulet was, especially during the intense cave-in at the end of Paradise. I think they just had a brain-fart on that part.

Mankar Camoran's Commentaries on the Mysterium Xarxes are nothing more than rambling and only serve as a guide for potential Mythic Dawn members to join the faction.

I do agree with you there about the ramblings, ramblings don't always mean that what is being said isn't true. I am hesitant to disregard something written by the only guy who can wear the AoKs without having to do with royalty. Especially when it is written about Akatosh and Oaths and stuff.