Ari Haswari (Rudolf Martin): The terrorist and double agent engaged in a tense cat-and-mouse game with Gibbs, leaving tragic consequences in his wake.
Trent Kort (David Dayan Fisher): A manipulative and enigmatic figure adept at playing various sides against each other, making him a formidable foe.
Paloma Reynosa (Jacqueline Obradors): Her quest for vengeance and ruthless tactics against Gibbs added a chilling intensity to the series.
Harper Dearing (Richard Schiff): Known for his calculated acts of terrorism that deeply impacted the team, showcasing the emotional toll of his actions.
Tobias Fornell’s Adversary (Joe Spano): The unnamed villain who targeted Fornell and his family, providing a personal and haunting threat within the show.