I love Black Haze, but I wish it could have just ended when he went back to the demon world. It would have been pretty good to end at a bittersweet note. (like princess Kaguya) Sometimes, happy endings and fully resolved plots can be too cliche. although unresolved plots can be frustrating as well. Now, we're left with a webcomic that will never get updated unless someone does something drastic.
Chinese novels are a lot more liberal towards incest/pseudo-incest depictions of relationships. From what I have read, a lot of romances start from sibling-like relationships. Calling each other in a familial way will almost always signify a sense of closeness between two characters, especially when they are not related. There are a lot of tropes that deal with these kinds of relationships.
In this case, they actually are twins. Once people read more and more Chinese novels, these kinds of tropes would be more unsurprising as time passes. it's not really a big deal.
Chinese novels and manhua pretty much have similar tropes though. but Sure!
Usually inter-dimensional travel novels, like Quickly wear the face of the devil, have the incest arc (brother/brother or father/son or even both), so I'm not gonna bother stating those anymore. But If you also want recommendations on those, then just tell me.
1. https://www.novelupdates.com/series/every-day-the-protagonist-wants-to-capture-me/
2. https://www.novelupdates.com/series/ive-led-the-villain-astray-how-do-i-fix-it/
3. https://www.novelupdates.com/series/rebirth-of-chen-an/
4. https://www.novelupdates.com/series/rebirth-of-the-wolfish-silkpants-bottom/
5. https://www.novelupdates.com/series/its-not-easy-being-your-love-rivals-big-brother/
Currently, these are the ones that I can remember. The last two novels are the ones that have the incest trope as their main thing. For other unmentioned novels, either, I can't really remember or they are just too shitty to recommend to people.
(Usually though, these kinds of relationships are more prominent in hetero harem novels/manga, which I honestly hate reading.. heck, even harem BL novels suck. It's usually because they are more focused on collecting boys than developing an actual plot.)
The sister makes me not want to read this manga anymore. There doesn't seem to be much going on with this manga anyway; Just the usual drama, sexual tension, and angst plus shitty side characters who are trying to make the MC and ML's lives worse.
These days authors are trying to spice up their works with crazy or murderous characters and lots and losts of angst. However, it ended up being repetitive and useless to the actual plot line. Sure, during the first few mangas/webcomics they were interesting (ex. Killing Stalking/ Viewfinder) , but now, authors are just using it to look relevant or to lengthen the story some more.
The story just began you have to wait.