As a child, Reiner was rather quiet and meek yet at the same time very loyal and driven. Reiner gained a newfound self-confidence, though it was quickly shattered when Marcel revealed that he was not chosen for his abilities. Reiner began incorporating elements from his personality into his own. He became more decisive and assertive, even willing to threaten Annie and Bertolt to ensure they followed his orders, yet also deeply caring and genuinely desiring to protect them.