Reiner Braun is a fictional character from the popular anime and manga series Attack on Titan. He is a member of the Warrior Unit sent to infiltrate the walls of humanity. Reiner is known for his strong physical abilities and his dual identity as both a soldier and a Titan shifter. Throughout the series, Reiner struggles with his loyalty to his comrades and the mission assigned to him. His character development highlights themes of conflict, identity, and the moral dilemmas faced in war. Reiner's complex personality makes him a significant figure in the overarching narrative of Attack on Titan.