Shit like this is why Terasu never managed to get published as normal mangaka. Like come on dude at least he finished it but that last drawing clearly indicates he was going to do a bit more than gave or up ran out of time.
To be honest, this story is boring. I won't deny that it has some great panels, but it never really built up any romance to make the betrayal feel more impactful. At the very least, it should've shown the sister gradually falling for him, but it didn't. Trying to force the idea that the guy loves the ex-tomboy just feels unnatural. I prefer Tsubame's story, even though its development was short, you can clearly see her getting more and more corrupted with each chapter. Here, the corruption happened entirely off screen
To be fair i doubt he needs to be published now with the cult following he has from the donations for his fanbox or whatever. Dude probably earns more here.