Baeksa wasn't the one who killed Muyeong it was his step father, Yehwa, while Baeksa was suffering from one of his delusion fits. When he came to and realized what had happened he sacrificed a part of his dragon pearl to bring Muyeong back. Whether he did this out of the good of his heart or solely 'cause Muyeong holds an important piece to how Baeksa can gain full control over his body is yet to be revealed.
The case with Yehwa and whether he wants to come back alive or not; he's been dead lol Baeksa alludes to Yahwa's body being like an empty vase when he compares it to Muyeong's body which was more like a vase full of snakes. It's kind of a metaphor for whether or not the soul inhabiting the body had any will to live. I've also got a theory that Yehwa secretly hated Muyeong, but I'll hold off on that till more is revealed.
Ah thanks for the explanation I find this series a lil confusing at times. I wish we kinda knew more about the stepfather and his thought process.
I think as Baeksa continues to live in his body we will get to see more of his memories and his true feelings about everything.
I don't think he fully hates Muyeon, but I do think Yehwa might hold a lot of resentment and maybe feelings of betrayal towards him for letting him suffer the way he did.
Like tbh both mc's are morally dubious. I for sure do not feel bad for the guard dude like having feelings for your adopted dad is weird bro. 2nd he's always wining about the imogi giving his dad's body back but like let's be honest I think the dad is dead or some part of him doesn't wish to return. And like the imogi is so mean so when he got "ravished" it was kinda deserved like bro you literally killed homedude striking your arm through him. Anyway their love hate dynamic is so good and I do hope for an eventual falling in love with each other sequence.