It is time, <name>. Take these ashes and look for the furbolg that Kodian spoke of. If he went to seek Ursoc, he will be near his den, north of Grizzlemaw.
You will need his help. You won't be able to defeat Ursoc alone.
Once you've defeated Ursoc, use these ashes to purify his spirit. Only then will we know whether our efforts have been in vain or not.
area. Talk to Tur Ragepaw. Ragepaw is a druid, and will shift in to bear, moonkin, or tree form when you're ready to begin. He will stay in the selected form for the entire fight.
On victory:
Spirit of Ursoc says: I thank you all. The druids of old were wise to tear down Vordrassil, for its roots seep deep into the dwelling of an ancient evil.
Spirit of Ursoc says: You know their kind as old gods. Beware Yogg-Saron, the beast with a thousand maws. His evil extends beyond Vordrassil's roots.