The beast is powerful. It has strong physical defense but is vulnerable to magic, and also very vulnerble to chain damage. Element: Nature (weak against Star).
A good strategy is to keep luring it so that Yurick may cast spells on it. Zael can then use Yurick's fire magic circles to imbue his blade with the fire element and then attack. After a long battle the beast retreats.
It also appears at the end of Chapter 15 .
In a book found in the Library, Zael learns that in times of crisis: "The Guardians will send forth their emissaries to guide humanity and aid them to avert the danger." Despite the violent first encounter, the Forest Beast proves to be an emmisary of the Guardians in the guise of a beast. In Chapter 38, the Forest Beast appears to Zael and his friends to guide them toward Lazulis Castle. The beast guides them because Zael is the only one who can stop the Outsider's power from being misused and exploited, and only Zael knows that the destruction of the land can be stopped by sending the Outsider into space.