Can't really get into it. The translation makes it super hard to understand what's going on. I'm not sure who MC is, but I think the demon sparrow vampire dude is, and he then gets... enslaved?? by white haired dude (I assume he's ML). Something about drinking white haired dude's blood, has the demon bound to him, I think by his literal heart according to the art. The story has a kind of slow start I think, especially with giving the audience answers to their questions. This would be fine if the translation allowed you to sink into the story and art, but unfortunately, that's not the case at all. The dialogue is overly flowery with terrible sentence structure. It's really not worth it, so I dropped it pretty quick.
Nagano Hymns