Reiner was rather quiet and meek yet at the same time very loyal and driven. He believed that if he became a Warrior then his Marleyan father would come back and deluded himself into thinking he would still cheer him on as he fought the Eldians even after he rejected him Because of his motivation, Reiner was very desperate to become a Warrior, even going as far as to accuse Galliard of being an Eldian spy when he belittled him However, after he was chosen to inherit the Armored Titan