Reiner Braun is first introduced as a member of the Survey Corps in the series 'Attack on Titan', where he appears to be a brave and loyal soldier committed to protecting humanity from the Titans. However, it is later revealed that Reiner is not only an operative of the Marleyan government but also the Armored Titan, one of the key antagonists of the story. His background as a Warrior candidate training under Marley adds layers to his complex personality and internal struggle between his true allegiance and his bonds with his comrades. Throughout the series, Reiner’s character evolves from a seemingly honorable soldier to a tragic figure caught in the throes of war and his own moral dilemmas. His themes of identity, duty, and the weight of choices resonate strongly within the broader narrative of 'Attack on Titan', making him a deeply compelling character.