Daredevil Season Three introduces Benjamin 'Dex' Poindexter (Wilson Bethel) to the Marvel Cinematic Universe as a mentally fragile F.B.I. agent turned psychopath assassin hired by the scheming Wilson Fisk, a.k.a. the Kingpin (Vincent D'Onofrio), to wreck the life of meddling vigilante Daredevil (Charlie Cox).
Episode 305, 'The Perfect Game,' acts as an origin story for Poindexter after the huffy agent is assigned to babysitting duties, overseeing Fisk's cushy house arrest for the ousted criminal kingpin turned snitch. Fisk, looking to unleash a new villain on the city, explores Poindexter's past: his entire life whittled down into a cardboard box as dredged up by Fisk's personal fixer Felix Manning (Joe Jones).
Stepping into his past, Fisk learns Dex was once an orphaned ward of the state placed in the care of the Lyndhurst Home for Boys. The young Dex was extremely proficient with his hands and showed promise as a future All-Star baseball pitcher, even sporting a little league uniform featuring a familiar bullseye insignia on its cap.
When he was pulled from the mound despite being on the verge of pitching a perfect game — something the boy hoped would bring back his parents — a devastated Dex gripped a baseball and launched it, "accidentally" killing Coach Bradley (Gary Hilborn) mid-game with the ricocheting ball.
Dex was then evaluated at the Riviera Psychiatric Institute and placed in the psychiatric care of Dr. Eileen Mercer (Heidi Armbruster), who readily identified the budding career killer suffered from Borderline Personality Disorder and psychopathic tendencies. Years later, a teenaged and emotionally-needy Dex threatened to kill Mercer because she was soon to die from cancer, ominously telling her: "I want to kill you for dying."
His dependency issues would persist, even as Mercer instructed Dex to stick to a rigid structure to better help his mental health. This lead to a stint in the Army and a position as a worker at a suicide prevention hotline, where he veered off script — nearly convincing one caller to murder their abusive step-father instead of taking their own life — and grew obsessed with co-worker Julie (Holly Cinnamon).
Years later, while working for the F.B.I., Dex uses his uncanny marksmanship to help rescue Fisk when his government transport comes under explosive attack by the Albanians.
A seemingly chance encounter with Julie, now working at the same hotel housing Fisk, further unravels the already fragile mental state of a barely-keeping-it-together Dex, who has since been put on paid leave while under investigation by the Bureau for his role in the rescue — a story that makes front page news on the latest edition of the New York Bulletin.
Dex's loss of his desperately-needed rigid structure makes him prime prey for the machinations of Fisk, who manipulates Dex into suiting up as an impostor Daredevil and attacking the Bulletin, where he leaves a trail of bodies when looking to assassinate a key witness who could expose Fisk for manipulating his way out of prison.
When met with an inquiry about his identity, Dexdevil says "I'm Daredevil" — but Bullseye has been born.
In the Marvel Comics, the deadly accurate supervillain emerged as the archfoe of Matt Murdock, once murdering Murdock's lover Elektra before later killing former girlfriend Karen Page with Daredevil's own Billy Club.