YEAHHHHHH WOOO BEST GIRL STAYS ON TOOPP!!!!!
I am a certified Mai hater, but I will admit fully and completely that she really showed her best in this arc. Best Girl Ajisai probably wouldn't have confessed without her encouragement, and it's also nice to see that their relationship despite loving the same girl is really close.
My largest issue with Mai is that it always felt as if she treated Renako like she owned Renako- that her immense love overruled her autonomy. Sometimes this would be really damn obvious like in chapter 14. Other times it would subtler like when Renako ran away with Ajisai and Mai crashed their cohabitation. In one way or another it always seemed like she was asserting possession over Renako.
I'm still not too sure how to put it, but this arc showed something different. She actively aided her opposition because she had absolute trust that Renako would choose her. It's different. It felt like before she was forcing events to happen to bring her closer to Renako, but now it feels like she's letting Renako choose her. Her love before manifested in games and gambits to trick Renako to love her. This love manifests as certainty that her and Renako's love is true and destiny.
I'm still wary of Mai. I'm not sure how well this certainty will last since Ajisai "stole" her place as Renako's destiny. Still, I can see how a harem end could work now. I would really prefer for Ajisai and Renako's moment to last for a while longer, but I wouldn't feel bad rooting for a harem end
Edit:
Reread chapter 14. I still stand by what I said here, but she really needs to give Ren a proper apology- not one where she endangers herself if she's not forgiven. I really don't think it'll happen though. I'll just snort a brick of copium and imagine that in the far future, they've been adults for a while. They reminisce on their love story and Mai realizes that she was pretty scummy in that moment. They talk it out, and Renako forgives her properly. (This is heavy, heavy cope)