One of the main themes could be the concept of the magical girl system itself. It might explore how the system is structured and what it means for the girls involved.
Often in such stories, there are supporting characters like the friends or family members of the magical girls. They may not have magical powers but can influence the magical girls' decisions and emotional states. For example, a best friend from school might notice the strange behavior of the magical girl and try to figure out what's going on, adding an extra layer of complexity to the story.
Probably not. Bakugo's personality and interests don't really align with the typical themes of shoujo manga. He's more focused on being a powerful hero and fighting.
It's difficult to determine if it's a good read without actually reading it. However, if the author is known for creating engaging characters and interesting plotlines within the isekai and magic genre, then there's a good chance it could be an enjoyable read. Also, if the concept of 'late magic' in an isekai world is explored in a unique and captivating way, it would add to its appeal.