What? Why did the kid been poisoned when little? And then, cursed? What really is the sys...

What? Why did the kid been poisoned when little? And then, cursed? What really is the system? Why the system feels like another person mana? Why the Mother of ilya was murderer when he was a kid? Why the gossips about how the marquiss suddendly die after they adopted the ilyas Mother? Why the fortune teller eat the gem? How come he knew about the system? And the system doesn matter anymore? JUST WHYYYY