Light Leaping is when elves travel on a beam of light. Their bodies break down into tiny little particles. Leaping crystals are used for this process. The crystals manipulate light in a specific way so, depending on what facet is used, it can take you almost anywhere. Nexuses are used to keep all of the particles together so you don’t fade away during light leaps. Once the nexus bar is at 100%, you are able to take it off and get a Pathfinder.
Fading can occur when a person does not have enough concentration to leap and does not have a nexus or for various other reasons that would cause them to lose part of themselves. As a result of this, murder by light leaping is possible in two specific ways. If someone broke the leaper's concentration by inflicting pain upon them or breaking their concentration in any other major way, it would break an elf's focus through a key part of the particle transformation. An alternative way would be shining another light, which would hence lead to the person leaping to two places at once leaving not enough of them in either place. Cyrah Endal's death where she faded was actually a murder in this fashion.