Legion features a character named Haller.
Legion ( David Charles Haller ) is a fictional character appearing in American comic books published by Marvel Comics . He is the mutant son of Professor Charles Xavier and Gabrielle Haller . Legion (TV series) . Dan Stevens stars as Haller , a mutant diagnosed with schizophrenia at a young age . Hawley wanted to show Haller as an `` unreliable narrator '' , including mixing 1960s design with modern-day elements , and filming the series through the title character 's distorted view of reality .