I don't know much about this flask besides what I learned from the Sphinx Aphyne.
You can find her sometimes just up the hill where you enter Volcanus. This object
must be well guarded for I have not heard much from those who have journeyed into
that land of fire.
A fortress well guarded from tower to door
The prize waits inside but take care I implore
Taking this flask can be accomplished I'm sure
Getting safely away might require a war