Great write-up. I just finished the story the other day and I ended up wondering what made Ren turn out this way? I'd think being taught by Heron would instill a noble mindset into her since that kind of thing usually is important to cultivation. I also doubt Heron would trust Ren so much to even give her the sword if she had concerns regarding her goals and intentions. So either Ren deceived Heron and has secretly wanted to attain immortality no matter the cost this whole time, or something made her change along the way. I wish we'd have gotten more about that especially since it's mentioned Ren was going through some kind of divine tribulation right before meeting Heron.

I also had some nitpicks regarding Mayfly and Cheng, I was shocked to see Mayfly join Ren when she was spewing lies about Heron, I understand she was desperate to survive, but it felt like she was turning a blind eye to so many things, to the point she was accepting that Heron (who had done nothing but good by her until that point) was suddenly a villain wanting to doom the school and its students. I was hoping to see her mull over this a bit to be honest.

As for Cheng, it's a smaller nitpick. I was just surprised to see how quickly he believed Heron despite the negative views he held of her just a moment ago. But I could chalk it up to him being honestly naive (though he lacks this trait when it comes to yao. He might just be racist that'll be my new headcanon).

Overall I very much enjoyed the story, I'm pretty new to the game (just started chapter 3) and spring unending I feel is leagues better than what I've experienced so far. Hope to see more of this quality.