Powers and Abilities
According to Deerhound, the Rave plants the user acute knowledge the necessity arises. This allows Haru to call upon the other forms of the Ten Commandments, minus the original final form, and probably the combination attacks.
When Shiba destroyed the Sinclaire and the Overdrive occurred, the Rave of Knowledge was scattered across the continents. Upon the year 0065, it was guarded for fifty years by the deceased Azure Sky Warrior, Deerhound, whose spirit borrowed the form of a bear.
After Deerhound entrusts Haru with the rave, he pledges with Haru that "there must never be another war, that's why the Rave power exists, to promote good and to destroy the source of evil." With Haru giving his solemn vow, Deerhound gladly departs to the afterlife.