What the... It regenerated? Not only that, it actually looked stronger than before. Okay, this was problematic, to say the least. What was also problematic was the toxic gas that was flooding the entire area, making it hard to even breathe, let alone fight properly. This was bad, really bad. If the dragon could just recover like that, then how could they ever hope to defeat it?

It was then that the Azoth finally decided to speak up again. -"Master, I may know a way to beat this foe".
"You do?," Felt called out. "Quick, tell us then!"
-"Okay then. Now, listen closely. There's an Alchemy Item called the Dark Water. It hampers healing techniques and drains away the energy of those affected. In fact, it's quite similiar to the Miasma this dragon is using. If my hypothesis is correct, it should make it impossible for the creature to recover, allowing us to finish it off."
Felt wasn't convinced. "Wait, if it's using the same stuff, then how will it work? Shouldn't it be immune to it?"
-"Possibly," his blade admitted calmly. "The creature might be immune to the effect of the Dark Water. I cannot be sure of this until we've tested this.
"Wait, then why are you making me make this item?"
-"Because obviously simply stabbing it alone isn't working," the Azoth stated.
Having no real counterargument against that logic, Felt gave in. "Okay, so what do I need to do?"

One short explanation later, Felt was focusing on creating the new weapon. Similiarly to how the other items were formed earlier, orbs of mana started to flow from the alchemist's body towards his hand. Unlike how the other items were formed, a sphere of darkness was forming in his hand rather than the shining spheres the other creations made. Regardless, the main process was the same, and quickly a flask-like shape was forming in Felt's hand, some kind of blackish smoke emanating from the opening. Strangely, it did indeed looked suspiciously like the very miasma the dragon was using against them. 
"Well, you don't win if you don't try...," the alchemist mumbled, then threw the newly created item at their foe.