The Great Demon Body is indeed different from that of mortals. No poison in the mortal world could possibly cause her any harm.
The only thing capable of poisoning her would be the Great Dao Poison.
Furthermore, fatal injuries feared by mortals, such as beheading or heart extraction, are not deadly for a Great Demon.
To kill a demon, one must completely obliterate the Demonic Thoughts.
The most fundamental power of a demon comes from Demonic Thoughts. As a core that absorbs Demonic Qi to power itself, it can reconstruct the demon's body. Even if the demon's body is chopped into pieces, it doesn't matter; as long as the Demonic Thoughts are not extinguished, they can be revived.
Of course, this is an ability only possessed by demons above the level of Great Demons. For ordinary demons, like Hu Yuling, once killed, that's the end.
