I think it's the voice that gives him negative thoughts and Shin thinks of it as a another person in his head.
Yeah I think it's just Shins intrusive thoughts trying to get him away from Wolfgang with all that "you don't deserve him" crap and to ensure that Wolfgang will marry a woman, so that the land gets a queen and all that.
Probably also him being afraid that he mistakes his love in Wolfgang for love in power.
thats so upsetting ... shin you liked this golden man before he even became a king... but ig thats what bad thoughts do to you
so. İs dark shin a part of shin...? Like his actual personality? Or is it an intrusive thought ... like are we supposed to accept dark shin as shin’s own thoughts or like a seperate existence due to ☆ mental illness☆