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