The Nephilim are enormous automatons crafted by the Zula. Powered by blue sap, they are mechanical giants that vary in size - the shortest being just over 10 feet tall, some being more than 100 feet, and the largest were about 4500 feet. Often described as the sons and daughters of the Great Spirit, they were originally built to assist in the construction of the Zulan metropoli worlds before eventually forming relations with humans.
The Nephilim were relatively benign beings when they were first constructed. However, in order to process the numerous complex movements they had to make, they were given highly intelligent minds. These minds eventually developed desires for relationships and thus, they intermingled and bred with humans despite being divine machines. They would do so by forming a spiritual bond via dreamwalking with a female to induce the virgin birth of a child, a process comparable to parthenogenesis. These children were born with extraordinary powers, and according to legend are the ancestors of the various dreamwalking orders across the world.
During the war between the Zula and Goar, the Nephilim became the primary defenders of the various Zulan strongholds. However, some of them would become corrupted with dark magic and would turn against their masters. These corrupted nephilim were so powerful that it took the Great Spirit's intervention to stop them. The Great Spirit sent forth a deluge that would bury the Nephilim beneath the waves in an event known as the Great Flood.
In 1954, a colossal Nephilim named Jira attacked Japan after being awakened by Id that began to appear in response to post-war fears of the bombings of Hiroshima and Nagasaki. Jira was the first enormous supernatural creature to be documented in the modern day and thus it received the nickname of Kaiju. The term Kaiju would go on to be referred to any colossal supernatural being. Further research on Jira would also lead to the discovery of the lost Zulan city of Kageshi.