Armin Arlert is a childhood friend of Eren Jaeger and Mikasa Ackermann who is often considered the "brains" of the group. Armin is often withdrawn and keeps to himself, but he becomes reliable when it matters. He can lack courage and doubt himself, but his ability to think of solutions in battle makes him a valuable team member. But, this also made him dangerous is a lot of ways. Especially his new obsession over Mikasa.