To this day a lot about the Sixteen is still debated by many philosophers and historians. This comes from a few issues, mainly that who make up the Sixteen is still debated as well. The conventional thought says that from birth these Sixteen were selected by fate, supposing Fate in a personified form. Many historians stand by this opinion, though they rarely reference Fate and keep who did the choosing more ambiguous. A newer school of thought, who are currently in the process of going through all of our records and histories and writing their own annotations and new versions of the stories, states that the Sixteen were actually chosen by their own actions. They say by doing great and terrible things they made themselves Sixteen, worth the notice of the Gods. Yes, I am in fact talking about my contemporaries the Mortal Right. Then there are the followers of the Son, who believe that a greater force created the Sixteen as a test for the gods, to see that if they were worthy of the task put before them. In order to keep this a history I am not going to share my own opinion on the matter. I will say that I believe that the Sixteen did in fact know there own nature, but I only share that so that you can have a better understanding of the events that happened.
It is at this point, shortly after reuniting with the Copopan Princess, that the Heroes started to hear about the Sixteen. The party decided that they should go to Long Garden for help, the city run by Halflings and Gnomes, in order to form an army capable of battling not only the North Men, but also the evil forces that surrounded themselves around Lord Stannis, the once good. This journey was fraught with dreams, starting to awaken their awareness to the existence of the Sixteen, they all became more and more interested in this mystery. After reaching Long Garden it was decided to split the party into two groups: One to help build up the defenses and the other to scout the surrounding area. Lucius Rastelli and Servantes, the Duo of Blood, were captured by the Goblins and shown before King Eric, the Strange. They were able to get some information about the Sixteen, and what they might be. They also learned that King Eric thought of himself as one of the Sixteen, despite the fact that he was reluctant to admit his suspicions.
How King Eric came into knowledge about the Sixteen, as well as start to suspect his own identity as one is connected to the same reasons that he is named by his people as the Strange. That is because of Eric’s history, one of education and high learning despite his race. This could also come from the fact that he was physically different from most other Goblins, he was constantly separate from them. Growing up without a father, despite illegitimate children not being uncommon, probably was what led him to such fervent worship of Grumsh, whom he saw as a father figure. When this strange goblin started to bring the different tribes together he must have seemed like a Messiah to these Goblins, who knew nothing of tactics and were dumbfounded how tribes smaller than them led by Eric could so easily defeat them. King Eric claimed that Grumsh talked to him in his sleep, telling him of the Sixteen. This seems like the most logical reason for how he knew of the Sixteen, which is why he is still considered as one of the Sixteen.