Report back to Donova Snowden with your findings.
The greenish substance inside the cauldron appears to be similar to what you found in the flask. This strange gooey stuff could be as corrupted as the furbolg that created it...
If the Winterfall furbolg are using it, does this mean that they will soon be as corrupted as the Deadwood tribe?
It would be best to report back to Donova with your findings, along with a sample of the liquid in the cauldron.