Sheoul

The isomorphic decay of this exotic element is known to interfere with the behavior of spacetime via massless radiation caused by the production of Weyl fermions. Sheoul is in this sense, a critical element in the production of many types of faster-than-light travel systems and is frequently coupled with aeon based engineering systems to produce a wide variety of spacetime modifying systems.

Importantly, they are very stable and only interact with other weyl fermions for the most part - able to carry charge for large distances without getting scattered and creating heat the same way electrons do. In this sense, sheoul can be used in conjunction with nano-engineering to create a class of computers which are far more energy efficient, stable and powerful. As such, sheoul is a prerequisite in many synthetic life-forms with digital brains and as such is highly contested.

Importantly, Sheoul is incredibly cost ineffective to produce conventionally and as such it needs to be mined from natural sources.