it's been years since I reading manga that makes me tingling with anticipation and exciting story like this,,makes me wonder why shit fantasy manga nowadays get anime with only resource enough to make 1 season and why not make this one
so this currently has 7 volumes, it seems barely enough for 11-12 episodes of the anime,
fighting plot goes very fast in the anime
and you have to remember, that most (almost all) of fantasy anime are adapting the novel, not the manga.
(people need to better understand that when they see an anime that is really different from the manga, but the story is from a light novel)
I believe this is straight from manga, so maybe wait until volume 10 or so
and also, the author has had success with Danmachi, he might want to take it easy