The Syns were created as living weapons, or a race of warriors, by some unknown entities. They only speak of dark vats where they were born, halls where they trained together, and an overwhelming, motherly, godly presence. Their memories are jumbled, and apparently mixed with memories of many dead people, presumably victims of the Syns' creators. Syns are living and thinking beings, not some robots; it's just not life as we know it. They are extremely honorable creatures. If we save their lives, they hold us as owners of these lives - and thus, everything they own.
(This advance is insufficient to repair damaged Syns).