Eren Jaeger, a boy whose mother was eaten during the invasion, vowed to wipe every last Titan off the face of the Earth, and joined the military determined to exact his revenge. But Reiner still performed good when taking into account that Eren had 3 titans in the last battle, two of which are the best titans for combat. Warhammer and attack titan are the perfect combination for fighting, providing both single target and multi target attack options, even then Reiner and Jaw held their ground against Eren, even.