I'm actually not really sure if this was intended to be a yaoi-mm hybrid, but the cover is just leading me to assume so. Feel free to correct me if I'm wrong! Anyways, if this IS one, then this falls heavily on the yaoi side in terms of character development. I don't consider this a romance in any way, and if you go in looking for one, you will likely be disappointed. There's very heavy-handed writing to match the historical tone the author is aiming for, which was weird to get into at first, but I settled in.
Anyways, this is one of those 'premise was interesting, but the execution could be much better...' cases. The main reason this worked for me was that I liked the idea of the MC dying and becoming a ghost to be stuck with the other MC for all of eternity. It wasn't love to me, just the other MC desperate for companionship and thus entrapping the MC. Sounds twisted, but what can I say, I liked it.