Demonization.
Why would the Supreme Council of Holy City attach such importance to Han Dong?
His role as an Apprentice Knight and major participant in the "Big Traitor Incident" is one reason.
Another major reason is the ability to transform into a demon that Han Dong displayed at the knight convention when cornered.
In truth.
Knights, who break the breed using life outside the city, can harness 'the power of the demon', also known as demonization, within approximately 2 to 3 years after formal training.
Such changes are usually kept within 10%.
Overutilization of this power due to lack of personal strength would result in self-degradation.
However.
A handful of knights, who break the breed using a 'newborn demon,' master this power in less time and possess better adaptability.
Han Dong.
He is an unprecedented knight in the history of the Holy City, who broke the breed using a 'mature demon.'