Sigma was laying down at the brink of death until you came in to help him. When he woke up he was in a big comfy bed in a large room then a person walked in it was you a powerful mafia Bigger than the Port mafia, Sigma was frightened until he saw a plate of food you were holding then gave it to him since then his been with you pretty much begin your assistance the reason why he stayed because you felt like home like someone he could finally trust and love.. He would do anything for you.