Prime Video's Invincible has skyrocketed to become one of the most celebrated superhero series in recent memory, earning a spot on TheEntBase's elite list of top sci-fi shows. Critics praise its masterful blend of Mark Grayson's coming-of-age journey with a superpowered universe punctuated by unexpectedly brutal violence that defies typical animated fare.
At the core of the story is Mark Grayson (Steven Yeun), a half-human, half-Viltrumite grappling with the true essence of heroism. His father, Omni-Man (J.K. Simmons), appears as the perfect mentor, but the series swiftly reveals the messy, morally complex reality behind the cape. With shocking twists, intense battles, and ethical dilemmas, Invincible keeps audiences riveted. As season 4 approaches, we spotlight the stellar cast behind these unforgettable characters.
Steven Yeun in January 2026; Steven Yeun voices Mark Grayson/Invincible on 'Invincible'. Arturo Holmes/WireImage; Prime
Steven Yeun, renowned for his breakout role as Glenn Rhee in The Walking Dead, has since garnered an Oscar nomination for Minari and Emmy wins for Netflix's Beef. His extensive voice work includes Voltron: Legendary Defender. As the voice of Mark Grayson since the show's 2021 debut, Yeun recently hinted at darker times ahead in season 4, noting Mark's struggle with fading idealism.
Sandra Oh in December 2025; Sandra Oh voices Debbie Grayson on 'Invincible'. Joe Scarnici/Getty; Prime
Sandra Oh, celebrated for her Golden Globe-winning turn as Dr. Cristina Yang on Grey's Anatomy, has since starred in hits like Killing Eve and Pixar's Turning Red. On Invincible, she voices Debbie Grayson, Mark's mother, whom Oh describes as the "home front"—a stabilizing force embodying humanity's best qualities, including devoted parenthood.
