Thanks for the chapter!
Looks like the fox is earning it's keep. Would be really funny if turns out to be female and turns into a beautiful woman who teases MC later on.
Btw, not really explained well but in alchemy there are a multitude of fires that can be used in alchemy with each one either a requirement for a certain level of pill or for maximizing certain benefits from the pill while removing impurities or harmful side effects. Fuel for the fire could be certain reagents, type or amount of spiritual power, and what kind of container the fire is in like a kiln or furnace. Sort of like difference between a small wood campfire used by a blacksmith and an industrial company's furnace with heat measured in the thousands making complex circuits or machines.
For example, the Blood Burst pill Buihua took greatly raises the power and cultivation of the person who takes it for a time, but has a harmful side-effect of crippling the user and/or their cultivation for a long time without treatment which is extremely rare and expensive. An alchemist with the right materials, fire, and cultivation level might be able to make a higher grade pill that can also temporarily raise cultivation level of user but toning down or removing the harmful side effect although might require a certain level of cultivation to use without exploding or burning out from the boost. Like plugging a flashlight and powerful light to a nuclear reactor. Flashlight would overheat and burn out in seconds while light might be able to barely endure so will be bright and hot without bursting.
@BasicEden MC fixed it up during one of those scenes where he was doing things that weren't shown or told to reader. After all, didn't see everything he was doing for the week.