What if Darius is actually not who we think he is?
From lore hes a badass who hates cowards, wants noxus to be strong, and will decapitate anybody without a second thought.
But what if he isnt truly this man that we think he is, what if from the very beginning before he became an orphan, somebody had been pulling the strings.
Think about it for a second; he becomes an orphan and gets stronger from protecting his brother and essentially "grow up faster". He saw things that made him hate cowardice and contributed to killing his captain.
What if Swain and Leblanc are behind all this in order to make Darius an efficient pawn?
Sion declares he is no pawn of Swain and that he isnt his general because he seems to know something we dont, or his intuition is saying Swain is merely manipulating others to further Swains plans.
What if Swain or Leblanc saw potential in Darius, but had to get rid of things making him weak and not in his full potential; his parents.
They may have tried to get rid of Draven but saw how Darius became stronger for having something to protect, unknown to him he is a puppet.
He sees Noxus as weak with nobles and hates cowardice which is what Swain and Leblanc wanted; to get rid of enemies that can thwart Swains plans.
When Darius met Swain he was ok with him and saw a strong Noxus in him but didnt know Swain and Leblanc basically fed him into their ideals.
Darius isnt a unique individual, his quotes even show that as they are almost all about the same exact things: cowardice, strength, and crushing enemies. Darius is merely Swains pawn, something Sion refuses to be.