Reiner's personality has changed so much that both his mother and cousin noted that he seems like a completely different person. Despite the fact that they are enemies now, Reiner harbors little to no malice towards his former comrades, only sarcastically referring to them as "devils" while humanizing their actions and beliefs before his family. However, in spite of all his emotional issues, Reiner is very intelligent with notable leadership qualities, able to think clearly, analyze situations, and formulate effective plans. As Eren himself confirmed, he is able to think ahead and in the long term, able to accurately predict the consequences depending on the course of action taken, all while maintaining his composure.