Grimoire Of Zero is a an pretty interesting anime to watch.
Story 8: The story is pretty good, though it's does leave out some of the important details that are explained in the light novels.
The animation is produced by White Fox, for which I am a fan of because they do very good animation on shows like Re Zero Starting Life In Another World & Steins Gate.
The Soundtrack is pretty good but the opening soundtrack was different than I was expecting. That's not to say the opening is bad but I feel that a heroic fantasy theme would have suited the opening a lot better, though ending song is really nice.
One of my favourite character design are Mercenary & Zero. Though some some characters had bland design like Holdem. In the earliest trailer back in late 2016, his outfit was originally green but got changed to red so I think green would have suited him better because it goes well with his nobility background.
I like how the characters interact with each other & what they learn from each other.
I recommend this anime to those who likes to watch an anime that has a nice fantasy & with a more mature background & characters like Mercenary that are bit realistic instead being all fan service. Also you can read the light novels on zeromahouthetranslation website. Although not all of the light novels has been translated on that site but it is a good site to read & hopefully in the future it will get an official release & a 2nd season.