The lightning Dragon emperor aka Vildred revealed why he was sealed by his brothers instead of getting killed to get his position. And the root cause being something called the 'Mark of Sin' that Kahn heard for the first time.
Vildred then decided to explain exactly what it was to Kahn.
"Like I said, child… Dragons are the favored species by mother nature. And Royal Dragons are like its favorite children.
Each of whom is an embodiment of a particular element of reality since the moment they are born to the day they die.
If someone else kills a Royal Dragon, they will not be branded by the mark.
But if a Royal Dragon kills another Royal Dragon… they are cursed with the Mark of Sin by mother nature itself.
And the Mark of Sin would act like a beacon, telling the whole world about what that Royal Dragon did." he explained in a tranquil voice.
"This case is important especially if you're in the line of succession.
