Monsters and demons were different.
The former had no obsessions while the latter was born out of their obsession.
Monsters who became demons were harder to deal with and to put it in simpler terms, the difference was akin to a mentally unsound person and a mentally healthy person.
One could see demons as monsters who had a few screws loose in their heads.
Of course, this description was rather lop-sided but it was easy to understand.
For example, being wrapped in the magma rock was a monster who was mentally ill. Wouldn't this explanation be easier for others to understand?
After retrieving the Thunderfire Needle, Lin Jin looked at Zhao Jingyan. She understood what he was trying to say immediately.
"The seal our Phoenix Palace senior placed is down below. To undo it and release the exotic fire, we have to clear away what's above it," she said.