Written by Heartless of the Sekijitsu writing team.
Kyoukai no Kanata was listed as a dark fantasy series but in actuality only about 10% of the plot was truly dark. KyoKai is your typical moeblob KyoAni anime but with action and monsters. If I recall correctly this is actually KyoAni’s first attempt at animating an action series (is you don’t count Chuunibyou) and to be honest they did pretty good with the fight scenes.