Biochemistry.
Ever since Han Dong tasted the sweetness of the G-virus in "Mist", he decided to spend more time exploring the potential of the virus.
The reason why such a powerful virus would appear in the low-to-mid-range fate events was due to its inherent danger. If any other apprentice knight had obtained the virus, they would likely have undergone irreversible mutations in the academy, lost consciousness, and been executed by the knights.
Such a 'bioweapon' can only be safely handled by a scientist like Han Dong, who is able to reduce the risk to a minimum and maximize its potential.
Han Dong had conducted many experiments and utilized the "Glaze" transformation in the Stargazing Room.
This was Han Dong's first public display of his perfect biochemical form.
Technology.