Here is the description form anime network
"Zedd is a 15-year-old boy who lives in Calm. He is frustrated by his current daily life and feels that somewhere out there is a place where he can live more fully. One day, at the invitation of a mysterious wind, Zedd dives into a space-time crevasse, seeking the "answer" that might be there. Riding on the wind, he arrives in a world where warriors called "Shard Casters" fight endlessly with each other, using magical crystals called "Shards". With the power of the Shards, the Shard Casters are able to use magic and control monsters called "Spirits". Fascinated by that power, Zedd also aims to become a Shard Caster. However, he still doesn't know that residing in his body is "Amil Gaul", a mighty Spirit with the power to influence the world's future."
I liked it. Though with 51 episodes near the end it got a little long. I just really got into the characters and it was just really sad when in the end the main character was gone and everything just moved on. I guess I'm just a real softy that way.