Disclaimer: Might contain some spoilers.
Date a Live III is third season of Date a Live (no shit), and honestly, it's the best one so far. Until this time, characters felt too moe like, but in this season, characters feel more like.. people, story is more complex, which will leave your brain blown, with the great characters, awesome looking animation, and beautiful voice acting, it creates a very good combination. Definitely worth seeing, but i deeply recommend watching first two seasons first.
It's very difficult to say something about the story without spoilers, but i'll try my best.
Shido is after successfully sealing several spirits living pretty normal life, but after some time, new spirit appears. This new spirit has onee-chan visual, and overall is acting like onee-chan. Of course, the AST shows up, so in order to defend herself, Natsumi (the new spirit) has to use her abilities. She does attack which uses some kind of transformation. After successfully defending herself, she gets very, very angry at Shido and swears that she'll ruin his life. So she does some stuff (cannot say what cuz spoilers). After successfully sealing her spirit powers, Origami wants to kill spirits again, so she tries to, but fails. Then, some kind of crystal with voice, aproaches her, swearing that it'll give Origami powers to defeat all the spirits, and of course, Origami accepts. Then, probably main event of the anime starts happening. In 6 episodes, it completely explains what happend 5 years ago and what led to these events. Shido is sent back in time to change all this, saving Origami's parents, which completely changes her. In current timeline, Shido and his "team" is trying to figure out, who is this new spirit called "The Devil".
This is where i'll stop, since this is part where it's very story based.
Animation is still very beautiful, with the Date a Live look. There isn't anything bad to say about it, everything looks very colorful and smooth, characters look very good. Definitely pleasant experience for eyes.
Sound and voice acting is very good, but in some parts, characters don't sound so good/natural. But still, very amazing job done on the sound.
Characters are absolute masterpiece of this season. All of them feel more brave, less moe like, and imo, new characters are also great. But for people who don't like tsunderes, yeah, it will be kinda annoying experience. But overall, very good job on this too.
It's a great sequel, but one thing that is definitely annoying, is that at every major thing, that main character should do alone, everyone comes, speaks about friendship, and win. I would definitely welcome some more MC independence. But after all, still great, there's not many bad thing to say about this season, i'm personaly very pleased with this. I'll definitely lookout for new season, and i hope it'll be atleast this good. Definitely worth seeing, it's a great experience.