From what we know, all the Moais are connected via land, so it is probably something to do with the land itself.
If I am not mistaken, there was also a barrier, similar to the barrier Guthix created around the Eastern Lands that kept most godly power out.
The Elder Horn was hidden by Guthix and then Quin found it who was a played in one of the Eastern Land's storylines, but was then killed.
It doesn't take away reason that some type of sentient being was in contact with the Horn after Guthix hid and and Quin found it. We also know that the current where about is unknown.
As mention, it is very possible that the land itself also became a god. This being is probably who made the Eastern Lands and erected the barrier around the lands when the gods came to the world. It is possible that there is another God or Goddess as powerful as Guthix, Seren and Zaros is out there, but was banished from the world, but left the horn behind.
We know Marimbo became a Goddess because of the horn, if that is the case, it is very possible that Marimbo is from the Eastern Lands. Marimbo also killed the previous owner of the horn, the previous owner could have also been the one who possibly found the horn after the 'Grandowner' left the world.
We don't know much, but we do know that the Elder Horn was in the Eastern Lands for a very very long time and probably created a very powerful god/goddess and has the ability to create islands and possibly life. It also seems to indicate that Marimbo became a Goddess in the Eastern Lands and possibly brought all the monkeys over from the Eastern Lands. Which then lead to the corruption of many Gorillas who then became Jungle Horrors and Cave Horrors.
Guthix to Grandowner to Marimbo's siphon to Marimbo and then to Quin and is now in the lands of someone else. If I had to guess, the being who created the Eastern Lands is the opposite of Xau-Tak
Come the Sixth-Age, the world will need the World Guardian.
10-Feb-2017 11:45:39