I am not sure, but i think his 'darker side' was referring to manipulating the information to gain more _personal_ power over the king.
As a show of his more darker ambitions but I still really don't have any idea.
Wait what? Wait... explain
His 'darker side' is shown to wear the king's cape as a token to symbolize his desire to be in that position.
The word itself 'kingmaker' is used to describe someone who has indirect control over the throne through huge influence over the royal because they themselves lack the ability to be a candidate for it and rely on the royal being the puppet. Who to say that Shin wouldn't have seized the position for himself if he was a viable candidate instead? Especially with Wolfgang starting to disobey him and having autonomy in his decisions during the recent events. (like he promised in ch 20) and that scene where Wolfgang had to use the royal command over him, it might have made him realize that his power is still obsolete compared to the king. And the fact that as someone who is as control freak as shin, who to say this event didn't awake his 'darker' desires?
tl;dr: dark-shin is telling him to do this to monopolize power over the throne but shin is a good boy and is resisting him by still being loyal to his majesty.
that's right. there are two Shins. The King's Maker Shin and The King's Lover Shin. ngl his dark side hot asf
wait why DIDNT he do that? keep quiet about the writer and reveal false info? is that evil or sum it just sounds intellegent to me