THE MIX
To mix your materials you should go at Ivory Tower talk to the local gatekeeper and press move to an other floor,then click Underground Shopping Area(IT IS NOT A PEACEFULL ZONE).

10 moonstones shards and 1 volcanic ash generates 1 moondust.
10 moondusts and 1 quicksilver generates 1 Lunargent.(THE ITEM YOU NEED).
You totally need 5 Lunargents.

10 lavastones and 1 sulfur generates 1 Magma Dust.
10 Magmadust and 1 sulfur generates 1 Fire essence.(THE ITEM YOU NEED).

10Demons Blood and 1 blood root generates 1 demonplasm.
10 Demonplasm and 1 sulfur generates 1 Demonic Essence (THE ITEM YOU NEED).

YOU now mix Demonic essence with Fire Essence and you have Hellfire oil.

I Hope you enjoy your Mix.