Legion (2017 TV Series)

Diagnosed with schizophrenia, David Haller has spent years institutionalized, unaware that the voices and visions are manifestations of his unparalleled mutant powers. After meeting a fellow patient, Syd Barrett, David is rescued by a group of psychic mutants who help him unlock the truth: his mind is infected by a parasitic entity called the Shadow King. David must battle this powerful demon who has warped his reality since childhood.