The original modus operandi of creation for the Jyalagoa is perplexing. The only truly established method for the creation of a Jyalagoa is the placing of a daemonic being within a Jylaious, a Jylaious being a type of crystal found on the Dark Forgeworld of Tohpeir. The first creation of a Jyalagoa is a mystery, though it's known that it wasn't a natural formation. The accepted conjecture is that heretical tech-priests, thought to have a strong connection with the Dark Mechanicus, implanted a number of daemons simultaneously within a large Jylaious. What caused the formation of the first Jyalagoa within the crystal is thought to be the numerous preventives used on the crystal to prevent the daemon from escaping.