Dearhound reveals a few secrets about himself and the rave stones after Haru proves himself in battle.
Not only does Dearhound know Plue, but in a previous life he was one of four Knights of The Blue Sky who fought along side of Sheba and the army of Symphonia to defeat the Shadow Stones, a battle that only Sheba and Plue survived. Returning in the form of his favorite animal, a bear, Dearhound became the guardian of the Rave of knowledge. When all the Rave Stones are gathered their true power will be revealed which will probably have something to do with promoting good and destroy the root of evil so there will never be another war.
The Rave of Knowledge gives Haru the power to attack faster then the speed of sound and transform his sword to Silfarion, which is used on Schneider when he sneaks in to the temple to steel it.
Giving Haru the Rave Stone, Dearhound is free to pass on, but not before giving us a tantalizing hint that Elie has a mysterious power and resembles the Lady Raysha Valentine from 50 years ago.