I'm just thinking about how if the gender was swapped so many people would be calling this manga disgusting and cause a stir in the internet. Anyways ...
Now hopefully when she becomes full yandere mc doesn't become a pussy and completely chickens out. Hope he can take full responsibility and actually become a couple unlike some mangas where the mc just tries evading the girl the whole story until the end.
This really feels like something from the toaru universe with the introduction (excluding the isekai aspect of course). This got the 2015 LN vibes with the trauma and backstory.
At this point mc should just go the harem route and make them all happy. I won't be able to stand seeing the osananajimi and va getting rejected. As for the vtuber girl I'm not that deep into her character yet.