Esper

Esper is the term used in Evil Step for a person (or other sapient being) which is capable of using PSI.

In the context of Evil Step, PSI is a large assortment of powers and talents that are, thus far, not proven possible to use in reality. These powers are derived both from various reported powers by self-proclaimed psychics in real life, as well as the “esper” stock tropes that became popular in the 1970s and 80s, through works like Akira, Kimagure Orange Road, and of course Earthbound.