TMDb/Dune: Part Three Movie Jason Momoa returns as Duncan Idaho in Dune: Part Three. Discover how his character's resurrection is rooted in Frank Herbert's deeper lore. March 18, 2026 AceShowbiz - Dune fans have been buzzing ever since the teaser trailer for Dune: Part Three dropped, especially after spotting the familiar face of Jason Momoa. Momoa originally portrayed Duncan Idaho, the fiercely loyal swordmaster of House Atreides, in the 2021 adaptation. His character was a key mentor and protector for Paul Atreides, played by Timothée Chalamet.