Complex sentence: He was originally a member of the Algo army who was married with a daughter, but when the biomonster outbreak initially occurred on Mota, his family were killed in an attack; he swore to avenge his family and left the army to become a hunter.
Split into simpler sentences: He was originally a member of the Algo army who was married and had a daughter. When the biomonster outbreak initially occurred on Mota, his family were killed in an attack; he swore to avenge his family and left the army to become a hunter.