Where to start... Well first off the plot i think there are a few clichés but that doesn't take away from the story at all, its still an extremely engaging narrative. it just makes it more predictable sometimes. As the story is told through the eyes of the main protagonist and his 'companion' it gives a pretty cool insight to both personalities and how they can change as they over come challenges together.
The animation style isn't the best that i have seen considering it aired October 2014. However it certainly makes up for it in other areas. The fight scenes for example are completely unique and very creative, they aren't your everyday anime sword fights.
There is great character development you get to see some real changes happen with the main protagonist, which makes it even more satisfying.
The excellent use of soundtracks make the feels hit harder as well (which i'm sure you'll find out for yourselves). The background music fits perfectly with the roller coaster of emotions felt during this series.
I thoroughly enjoyed this series and would highly recommend it to anyone interested in this genre.