Recipe: Infernal Alchemist Stone

Found the recipe on the Legion Dalaran Patricia Egan and it's also not on the old school Dalaran Patricia, Unless you have done the pre quests you are not eligible to buy the recipe. So here is everything you need to know on how to get this recipe, here goes. You need to have progressed through the Legion Alchemy quest chain far enough to get the following recipes/quests.

The recipe can be purchased from Patricia Egan in Dalaran. However, to be able to buy the item, you need to have the Demonsbreath Crucible.

To get the Demonsbreath Crucible , you first need to pick up the quest A Fragile Crucible from Deucus Valdera in Dalaran. You then have to travel to Felsoul Hold. Make your way to [30, 83] and you should see a small jar/container on the ground to the right side of the altar.

Once you have this, return to Deucus Valdera and you will pick up the next quest in the chain, Lining the Crucible.

Lining the Crucible requires you to gather/buy 1x Blood of Sargeras, 1x Felhide, 2x Felwort, and 100x Yseralline Seed. Once complete, you then pick up the quest A Gnome's Assistance.

The quest A Gnome's Assistance requires you to kill an optional boss in Vault of the Wardens.

YOU NEED TO TAKE AT LEAST 1x Skaggldrynk potion with you. This recipe is available from Patricia Egan after completing an earlier quest, We Need More Powder!.

This is required for you to see the hidden door and unlock it to gain access to Grimoira. I have read somewhere that once you use the potion and unlock the door, any spare potions you may have will also be consumed. So maybe leave some in your guild bank and use Mobile Banking if something goes wrong.

The door is located to the north in the area where you kill Inquisitor Tormentorum. Go to the wall and then drink your Skaggldrynk. You will then see the hidden door and the lock. Unlock it, go into the room and kill Grimoira. Loot Bendy Glass Tubes required for the quest Vault of the Wardens: Bendy Glass Tubes.

I'm not too sure which, but it seems that you either need to step into one of the green swirls on the floor, or her frontal 'bile cone' AoE to complete the ' Submerge the Demonsbreath Crucible in Grimoira's bile' part of the quest.

And remember, you also need to kill the last boss in the instance (Cordana Felsong) to complete the whole quest.