From the announcement:
Millennia ago the ancient Mayans of Terra where chosen by their god and master, the winged serpent Kukulkan, to be elevated above the lowly tribes of the world. Their master, in reality a member of the powerful and technologically advanced Coatl race, lifted his willing servants up and has, over millenia, shaped them into a race of bio-enhanced warriors and zealous priests, eager to gain his blessing by slaying all those who would oppose his will.
Now Kukulkan has set his sights on Samaria, following mysterious energy reading mimicking the Coatl's own entropic power sources only to find their holy technologies bastardized by the lifeless machines of the CORE. This blasphemous act, coupled with an ancient grudge against the Alteghrans, the forebears of the Dragyri, have unleashed the full might of the Kukulkani upon all of Samaria.
Woe to the enemies of Kukulkan, may all tremble and despair!