Ok I have a theory that Skull Island used to be Azteca look at the clues.

• Xol Amul
• Ancient Tunnels Everywhere you go in Skull Island and nowhere else
• and the fossils hidden in the cave next to Zadok, and the Temple of Death

What Do You think. Do you think Skull Island is Azteca or It's Just a Coincidence.

Actually, if you paid attention to your Spiral history books Azteca was orginally all of the worlds for in the beginning before there was a spiral it used to be a planet covered with Frost giants, fire dragons, tritons and minor mortal creatures such as the dinosaurs of azteca. When the planet broke apart, many of the vast cities and culture of the Aztecs were separated and or destroyed in the process. As years passed, many of the dinosaur people of azteca on the different worlds (except one) died out and what was left of they're civilization were eventually taken up by animals and mammals that learned how to walk upright just like the aztecans had and evolved into more brilliant civil animals with actual fingers (the most evolved of all of these animals were the humans, however they're population in the spiral varies per world).

The ruins that you stumble upon in Blood shoals and all over skull island and the spiral are what remains of the aztecans which many modern day civilized worlds are plundering for either research or for treasures. Some of the worlds where there's no civilization on may have some still standing untouched ruins of the old civilization. What you see in Skull island are dug up ruins that many world powers are plundering for riches.

As for the ones you find in Blood Shoals, they are indeed the Aztecans from Azteca; the last world containing what remains of their civilization and kind. When Morganthe came a long time ago looking for ancient astral magic, she cursed the world by calling up a comet to destroy it (which remained suppended in the air up until the wizards chase morganthe to there) which led to some of those people to flee in order to preserved their kind.