Min never knew why the high priestess wanted him to accept the second daughter of the Minister of Defense's marriage proposal.
Was it even not enough of a reason to refuse someone because he did not love her? And suppose if he really loved the Lady Boram, what good would it bring to him?
He was a celestial warrior, for goodness' sake! He had to vow his loyalty to the kingdom and the high priestess. Min had to follow the high priestess everywhere, protect her from those who wanted to ruin her, and ultimately summon the White Tiger with her.
If he was to be honest, Min pledged his loyalty to the high priestess, not to the Goguryeo kingdom, not to the king, nor the crown prince as well. Well, he might be doing this because he was a celestial warrior, and celestial warriors are expected to become the pillars of the kingdom.
But screw all of that bullshit.