Keith Shardis

Keith Shardis was the head instructor of 104th Trainees Squad. He seemed to be a friend or have some sort of relationship with Dr. Grisha, as he knew Eren is the son of the doctor and praised Eren for his effort. He is a former Commander of the Survey Corps, and was in command when Wall Maria fell in 845. First Appearance Manga: Ch. 15 "One By One" Anime: Ep. 1 "To You Two Thousand Years Later" (Source: Shingeki no Kyojin Wikia)