A Certain Magical Index isn't a deep work. It's not written to blow your mind, it's not a genre redefining work. It's main purpose is to entertain.

And boy does it entertain well. Just the sole achievement of writing 45 volumes of novel (and that's not counting spin-offs and side volumes) and still being able to draw the readers in alone is outstanding. The plot works with various concepts and it's great to see that it can keep up the stakes without just simply one-upping the previous villain and inflating and ruining the whole power system like you would see in DBZ-esque works. Sometimes the peril is personal, sometimes it's the whole world or even the whole reality that's in danger, but it always gets you to root for the protagonists and hypes you up.

To expand on the "concept" part, as with the previous season of the novel, Index still draws from various myths and mythology systems. As I'm a sucker for works that mingle together multiple mytholgies, I might be a bit biased there, but Index really does this well. The usage of those mythologies is surprisingly well detailed and researched and even obscure legends and characters get their turn to be incorporated. In fact, sometimes what I've previously thought were just some random terms created for the Index universe were in fact yet another less know esoteric terminology from history. Truly educational.

And even when mixing together fantasy and sci-fi concepts, the overal system created for this coexistence is left without contradictions and seeming discrepancies get explained. This is in fact an occuring theme, simplyfing the technobabble (or in this case sometimes also magebabble) into layman's terms, usually through the mouth of the protagonist to level with the reader and to justify how it's possible for the characters to still stay in the game even as more and more big shots enter the ring. I think this is quite neat storytelling trick. Though yes, sometimes the babble can get out of hand, and especially the Kamisato Faction arc might get a bit confusing, mainly because it introduces *a lot* of new characters at once.

Which gets us to the characters in general. This is one of the main strenght of Index novels - the cast is colossal, but still with great variety both externally and internally. I dare to say that everyone will be able to find their favourite character even among the side cast. The flow of introducing new characters is also user-friendly, so you won't get lost in who's who (with the exception of previously mentioned Kamisato Faction arc, of course). Though, this "everyone gets a favourite side char" has it's own... inconvenience. Sometimes the story takes too damn long to go back to some of those characters, which of course might sadden the heart of a fan.

And that brings us to the fanservise part of Index novels. It would be dishonest to act like it doesn't exist. Yes, mixed with the storyline, Index novels also have some good old fanservices. But you what? I can't even be mad about this specific case. I'm fine with it as it doesn't deteriorate the story and it's more of a snack springled between the main dishes. Yes, this goes against my personal policy of bashing anime/manga/novels/whatever with fanservice, but that just show how great Index novel is.

One final thing that I liked about New Testament specifically is how it juggles with status quo and isn't afraid to make changes - the largest example can be seen in the latest volumes here, with the latest arc surpassing even the last arc of the previous novel season. Really, almost 50 volumes and the story still didn't get stale, what a great success.