Since before the discovery of the gates, most realms knew of the existence of the Kaiju. Despite it being a rare occurrence, some of the smaller specimens would occasionally find their way through a gate and terrorize the local populace for decades or centuries, before eventually succumbing to either old age or malnutrition. In those rare worlds where a dead kaiju either drifted ashore or (even more rarely) was killed, at least some of the abnormal properties of these titanic creatures have been known even prior to the discovery of the endless ocean. Their bones are, traditionally, one of the first discoveries a nation makes, due to their organic stability. Highly durable yet exceptionally lightweight, kaiju bone is often used in weapons, armor, or in decorative displays, and is often noted for its exceptionally lustrous and broadly pearlescent appearance in the latter. This is largely due to its near unique natural occurrence of boron allotrope γ-boron, which is more commonly synthesized in laboratories at high pressures and temperatures. Carving or working this material is exceptionally difficult, but due to boron’s affinity for hydrogen and nitrogen, it is able to be (and is traditionally) worked through nitric acid etching, a process that can take several days to strip away a noticeable layer, making Kaiju bone artifacts extremely time consuming to produce. The relatively inert nature of the bone, however, means it pales in comparison to the other compounds that can be recovered from a fresh Kaiju corpse. By volume, most Kaiju materials come in the form of mucosal membranes (and their associated emissions) or adipose tissue, which are used by the kaiju as an energy store, and generally are composed of either diborane or lithium borohydride. While volatile, if properly retrieved these compounds can be used as highly potent sources of energy.

Having covered the most common materials derived from the Kaiju, we can now delve into that most sought after: the trace amounts of element 126, colloquially referred to as Corticum, that can be derived from within a Kaiju’s brain. Usually carried in trace amounts, Corticum is the largest known semi stable element, proving an effective nuclear fuel, a highly active catalyzer, and a high density, high strength alloying agent. With a variety of uses, it has driven the Kaiju hunting industry to pursue ever larger prizes to extract their disproportionately large concentrations of Corticum.